This is a Necessary Assumption question. We know because the question stem is asking for an assumption the argument depends on.
The amaryllis plant goes dormant when its soil dries up. That seems like a handy trick and is probably an important adaptation. So, what about it? Oh. It looks like we’re jumping straight into a conclusion. If we’re keeping these as house plants and want them to really thrive, we should withhold water to mimic its natural habitat by creating a dry season for it. Well, I create dry seasons for my house plants sometimes, but they don’t particularly thrive from it. It might actually be nice to have a plant that has an evolutionary adaptation to negligent house plant owners.
This is a really common argument type. It’s the simplest argument structure there is: Premise, therefore, conclusion. A therefore B. It is never valid because there is absolutely nothing which links the premise to the conclusion. The premise and conclusion can be intuitively related, and these arguments can sometimes even seem reasonable on the surface. But a formal analysis shows us what a disaster this sort of argument always is. You can’t say “A therefore B” without establishing any relationship between A and B. Our answer will almost certainly be something that establishes some connection between our premise and conclusion.
So our premise is about the amaryllis’s natural habitat and our conclusion is about what we should do for our house plant amaryllis to thrive. We need something which links the plant’s well-being to its conditions in its natural habitat.
Answer Choice (A) No. We could not care less about what other plants do. The argument in the stimulus does not stray from the amaryllis.
Answer Choice (B) Well, first of all, this doesn’t sound true at all. Something that can handle a bit of drought sounds like an ideal house plant to me. But that doesn’t matter. It doesn’t have to be true. We don’t know if these plants are hard or easy to care for and we don’t care. Whether they’re harder or easier to keep than other plants has no bearing on our job in helping them thrive.
Answer Choice (C) No, though I can see why this might be attractive. If we’re trying to mimic its natural habitat, wouldn’t this be best? Well, yes. But are we trying to mimic its natural habitat? Not necessarily. We are trying to create conditions in which it will thrive. This answer requires the further assumption that its natural habitat is optimal for it to thrive. We do not know this. Life may find a way, but that doesn’t mean it’s thriving.
Answer Choice (D) Tricky. If it doesn’t thrive then it probably wasn’t dormant long enough. No, this doesn’t need to be true. There could be many other conditions required for this thing to do well, any one of which may explain why a plant might be struggling. Maybe it got too little or too much sun. We just don’t know. This does create some relationship between the premise and the conclusion, though, so it might be tempting.
Correct Answer Choice (E) This looks good, though the test writers do make some effort to disguise it since they never explicitly talk about thriving. But it’s there. It establishes that the plant’s dormancy benefits it beyond merely preventing it from dying. If its dormancy period only prevents death and there is no further benefit, then there is no reason to intentionally subject it to drought conditions. There’s a lot of room between not-dying and thriving. This answer provides us with something more than simply not dying. There is some benefit to dormancy other than just not dying. Now, we may help it thrive by withholding water because we are providing whatever this benefit might be. If this is not true, however, then drought provides no benefit whatsoever and, thus, cannot help us to thrive.
Here we have a flaw question, which we know from the question stem: “The reasoning in the argument is most vulnerable to criticism on which one of the following grounds?” Right away we know our correct answer has to do two things: be descriptively accurate, and describe the flaw of the stimulus. We also know what the wrong answers will do - describe reasoning flaws we’ve seen before, but don’t like up with our stimulus. Once we have a clear understanding of the questrion’s objective, we can proceed into structural analysis of the stimulus.
The stimulus begins with an if-then statement: if Blankenship switches suppliers, they will not turn a profit. Based on this sentence our speaker concludes that if Blankenship does in fact show no profit, it must have been because they switched suppliers.
Diagramming the relationships can help us see the conditional reasoning mistake being made. While we know that a switch in suppliers guarantees a lack of profit, we cannot simply switch around our sufficient and necessary conditions in the conclusion. The evidence presented by the author tells us that S (switch) → /P (no profit).
From here we can conclude only a few things. We could correctly conclude the contrapositive to be the case, that if we do in fact turn a profit we know the company has not switched suppliers during their production run (P → /S). We also know that if the switch occurs profit will be affected. However, we are not able to draw the conclusion that because we have the necessary condition of no profit does not mean we can confirm the existence of our sufficient condition - switching suppliers.
Knowing our speaker mistakes the information we can conclude from a conditional relationship, we can proceed into the answer choices.
Answer Choice (A) Answer choice A is not descriptively accurate. By accusing our speaker of circular reasoning, this answer claims the argument uses its conclusion as evidence for the argument. Without a statement telling us “the conclusion is correct because the conclusion is correct,” we can eliminate this answer choice from consideration.
Correct Answer Choice (B) This is exactly what we are looking for. This descriptively accurate answer choice correctly points out the mistaken conditional reasoning made in the stimulus. Simply because we know S → /P, this does not mean we can just switch the arrow in the opposite direction like our speaker does in the conclusion.
Answer Choice (C) This answer choice is also not descriptively accurate. Rather than shifting the meaning of a word over the course of the argument, our speaker confuses the direction of the relationships between terms that remain consistent in meaning.
Answer Choice (D) Answer choice D is not descriptively accurate. We have no information to determine whether or not Blankenship represents an exception case or a run-of-the-mill operation. Even still, Blankenship being a unique case would not change the conditional flaw presented in the author’s reasoning.
Answer Choice (E) This is not what we are looking for. Accusing the speaker of failing to consider some third possible event does not identify the mistaken reversal occurring in the stimulus. This answer choice aligns with the common correlation/causation flaw often presented in flaw questions - but that is not the issue here.
We know that this is a Sufficient Assumption question because we see “which one of the following principles, if valid, justified the…conclusion” in the question stem.
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it valid. Our rule/prephrase will look like: if [premise], then [conclusion].
The first sentence gives us a lot of information on pedigree dogs: pedigree dogs (including working dogs, like a shepherd or hunting dog) conform to org standards. We also know that these organizations specify the physical appearance needed for dogs to belong to a breed. The stimulus then says that the orgs don’t have standards for specific genetic traits. The author cites, as an example, traits that would have enabled dogs to do the work they were developed to do (like sense of smell or direction). This all sounds like important contextual information.
In the third sentence, we see “since,” a premise indicator. The author says that because the breeder will only maintain the traits specified by the organizations (premise), certain traits (like herding) risk being lost (conclusion). This seems like a logical conclusion based on the premise we just read, but it may not be our main conclusion. Let’s read on.
In our last sentence, the author claims these pedigree organizations should set the standard for working ability in dogs developed for work. First thing, this is the main conclusion; the whole stimulus is oriented towards this one statement. However, is this a valid conclusion? Well, why should the organization set these standards? Are they necessary for, as an example, an Australian Shepard who isn’t going to herd sheep? This is the gap in our argument.
Remember, we’re bridging this gap by forcing a conditional statement with our premise and conclusion: If [premise], then [conclusion].
The first two sentences help guide the rest of the information in the stimulus, but it’s really the third sentence that acts as the minor premise and major premise/sub-conclusion: working traits that certain dogs were originally developed for are at risk of being lost. Our conclusion is that these organizations should set requirements for the working abilities of working dogs. Together: If working traits that working dogs were originally developed for are at risk of being lost, organizations should set requirements for those abilities in those dogs. The correct answer doesn’t need to be a conditional statement, but it needs to have the level of certainty and language of the conclusion (in our case, prescriptive).
Answer Choice (A) This answer choice is wrong because it doesn’t address what our argument focuses on. This answer would come into play if setting standards for working traits risks the loss of other traits. Since we don’t know anything about what working traits could do to other traits, this is out.
Answer Choice (B) This is wrong because it’s only relevant to standards currently in effect; we’re talking about standards that are not and should be in effect.
Answer Choice (C) This is saying that organizations should make sure standards are respected; this isn’t relevant to our argument! We’re trying to argue for an additional category of traits to be included in the standard.
Answer Choice (D) Use the product/activity will eventually be put to? It’s not said that working dogs will be used for their working purposes, only that those traits need to be retained.
Correct Answer Choice (E) It uses information from the premises (ensure that products can serve the purposes for which they were originally developed, e.g. herding, hunting) and echoes the prescriptive language in our conclusion (organizations should attempt). Even though this isn’t a perfect repetition of our prephrase, remember that our prephrase is meant to help guide us to the correct answer choice by making sure we understand and can extrapolate relevant information from the argument.
This is a sufficient assumption (SA) question, and we know that because of the language in the stem: “Which one of the following principles… would justify…”
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it “valid.” Our rule/prephrase will look like: if [premise], then [conclusion].
Our first sentence is a prescriptive claim, with a concession: even though smoking is legal, smoking should be banned on flights. The first question we ask is: “Is there a reason this should be the case?” The next sentence attempts to give us an explanation: smoking exposes people to unavoidable harm. Our first sentence is the conclusion, and the second is the explanation/premise.
SA questions often take this form: the conclusion is that something should be done, and our premises attempt to support and validate this prescriptive statement, but it misses the mark. Why? Because the argument makes illicit assumptions.
Back to this stimulus. We could say: “Sure… the harm is unavoidable, but why should we punish the smokers? Why don’t we just prevent non-smokers from flying?”
The good news is that, in trying to make these arguments valid, the solution is simple: bridge your premise and conclusion through a rule: If [premise], then [conclusion]. Our premise here is that “smoking exposes people on planes to unavoidable harm” and our conclusion is that “cigarettes should be banned on all flights.” Our rule will look something like this: “If smoking on planes causes unavoidable harm, then smoking should be banned on all flights.” This is forcing our conclusion to be true by putting the premise and conclusion in a conditional relationship. We’re also trying to make sure that we retain the language/level of certainty in the conclusion when we create our rule. With the rule (or principle, to take the language of the stem) established, the sufficient condition is triggered by the premise and our conclusion is valid. Also a note, the answer choice may not be as straightforward as our prephrase. They could give us the contrapositive of the conditional, or introduce the necessary condition first, so pay attention.
Correct Answer Choice (A) This one perfectly mimics our prephrase. It’s broad, but that doesn’t matter because its scope includes our argument: People should be prohibited from engaging in smoking (or, legal activity) when (or, in those situations in which) that activity will harm people. The order might be confusing to some people, after all, the conclusion is introduced first in the sentence. However, because “when” is a group one indicator, this is correct. If you have trouble understanding this, review conditional logic in the core curriculum.
Answer Choice (B) This is incorrect because of the direction of the conditional statement. The “should be banned” and everything after the group 2 indicator “only if” should be switched. With the language in B, we can’t trigger the conditional and this leaves our argument untouched.
Answer Choice (C) The first half of the answer is pretty good! But “legal activity should be modified?” That’s very ambiguous. Remember, in SA questions, we strive for 100% validity. What would modifying the legal activity of smoking look like? We can’t just assume modifying means banning it.
Answer Choice (D) Read this answer choice very carefully – it’s very wordy, but it’s essentially saying that people should be excluded from situations in which their activity harms others in those situations. With respect to our argument, that would mean smokers should be excluded from flying. This is incorrect because our conclusion claims that smoking should be banned, not smokers.
Answer Choice (E) This is similar to C in that the first half of the conditional is okay. But when we get to the necessary condition, the answer choice pivots. We’re trying to make smoking illegal in airplanes and our answer choice is saying that it should be legal in all situations. This actually weakens our argument.
We know this is a sufficient assumption question because the stem says the “ conclusion...would be properly drawn if which one…was assumed?”
Sufficient assumption questions tend to be very formal. We’re looking for a rule that would validate the conclusion, specifically by bridging the premise and conclusion through the rule. Not only are we extrapolating the rule from our argument, but we’re plugging that rule back into the argument to make it valid. Our rule/prephrase will look like: if [premise], then [conclusion].
The first sentence is describing the features of some languages as they compare to English, specifically with kinship systems, and then makes a conclusion: people of other languages who have different words for different family members (like Hindi speakers or Korean speakers) evidence “a more finely discriminated kinship system” than English speakers do. This argument sounds good. Is the main conclusion of the argument? Let’s read on.
The next sentence goes into another difference between languages: different languages vary in the number of words they have for colors.
Our last sentence starts with “therefore,” which is a conclusion indicator. Not only is this a comparative conclusion, but it’s a very long one. However, we can break it down. Let’s just pretend language X is the language that has fewer words for colors than English. The conclusion is saying that X speakers can’t visually distinguish between as many colors as English speakers can. Before we get into the analysis, is this our main conclusion? Yes! The first two sentences are almost at once context, at once an analogy. The main conclusion is this last sentence.
The analogy they’re making is understandable: uncles are called uncles in English; doesn’t matter if they’re on your mom’s or dad’s side. That’s why we can say speakers “evidence a more finely discriminated system…” The word evidence is important – it’s not like English speakers don’t recognize that “father’s brother” is different from “mother’s brother,” it’s just that other languages have actual words to represent these specific relationships.
With the color argument, it’s a little bit different. It's about our senses. Here, we’re saying X speakers, because of their limited vocabulary on colors, can’t distinguish between, say, royal blue and navy blue. That’s a wild conclusion! What if they can distinguish and describe it, but they just don’t have a word for it? This is the gap between the premise and the conclusion. To mend this gap, we have to connect the premise and conclusion by tying “words” and “the ability to distinguish” specifically relating to our senses. Something like: having different words to describe something (color) is directly related to our senses’ ability to distinguish between things (colors).
Answer Choice (A) How does this fit into the argument? This is going back to the analogy part of the stimulus and adding more information to it. It doesn’t help prove that words are needed to distinguish things.
Correct Answer Choice (B) This wording is convoluted, but if it’s broken down, it makes sense! Each language will have different words for every sensory quality they can distinguish. Here, “sensory quality” includes visualizing all of the different colors. Yes, it’s very broad, but that’s okay - this broadness enables the validity of our argument.
Answer Choice (C) This falls outside of our argument. We don’t really care about categories, we care about how we perceive things within those categories.
Answer Choice (D) This is so close, but the word “categories” here doesn’t apply for the same reason we cited in C. If I swapped it out for “words within categories,’ and then swapped “important” to “needed,” the answer would have been good.
Answer Choice (E) This potentially explains why they don’t have many words for colors. But that doesn’t matter; we’re more interested in the reason why they can’t perceive or distinguish between colors.
We can identify this question as Method of Reasoning because of the question stem: “the relationship of Ping’s response to Winston’s argument is that Ping’s response…”
When dealing with a Method of Reasoning question, we know we are looking for an answer choice that correctly describes the structure of our entire argument. Our correct answer is going to fit the argument exactly. Our wrong answer choices likely explain argument structures we are familiar with, but that simply don’t apply to the specific question we are looking at. Knowing what the right and wrong answers are going to do, we can jump into the stimulus.
This question presents us with two speakers. Right away, we should recognize that there are two conclusions and two reasons behind them. In this case we are analyzing two speakers taking varying positions on proposed budget cuts by the public transit authority. Our first speaker explains the transit authority cannot avoid a deficit unless it eliminates some services. Winston says that because the other means of avoiding the deficit (like fair increases) are not an option, the suggested cuts should be made. While our first speaker ends with a conclusion that affirms a recommendation on an action, our second speaker takes a different perspective. Winston’s argument seems to make sense as long as we are in agreement on what things should be done. If the city is interested in operating with a deficit, that would be evidence it should be pursued.
Ping responds to the first speaker’s argument without addressing Winston’s overall conclusion. Ping points out that there is potential for the budget cuts to not lead to much savings because the cuts would affect riders leaving home during the day but returning at night. By pointing out a possible event Winston does not think about, Ping explains how the first argument actually does not have the evidence necessary to support the conclusion that the budget cuts should be made.
Answer Choice (A) This answer choice does not line up with the structure of our argument. While this answer choice states the argument “carefully refines terms,” we do not see the explanation of a term or disagreement with how Winston defined the different parts of their argument.
Correct Answer Choice (B) This is exactly what we are looking for! This answer choice correctly summarizes the different components of our argument by pointing out that Ping questions the first speaker’s evidence, but not the overall conclusion. We can confirm this answer choice by double checking to confirm Ping points out a group of riders left unconsidered rather than argue against Winston’s conclusion.
Answer Choice (C) We can eliminate this answer choice when it tells us that Ping is supplying a premise to Winston’s argument. Supplying a premise suggests that Ping is supporting Winston’s argument rather than questioning (weakening) the assumption on which Winston’s position depends.
Answer Choice (D) By claiming our argument introduces detailed statistical evidence, we know this answer choice does not line up with the structure of the stimulus. For this answer choice to be correct we would need to see a reference to statistical evidence, detailed or otherwise. Aside from that, this answer choice says the statistical evidence (that we do not have) is more persuasive - where does that idea come from?
Answer Choice (E) This answer choice does not line up with the structure of our stimulus most clearly because of the word contradicting. For this answer choice to be correct we need to see two ideas in the stimulus that don’t just appear inconsistent, but that directly contradict one another. Not only do we fail to see ping propose a solution as suggested by answer choice E, but we also cannot find contradictory ideas in the stimulus. We instead see factors that were previously unconsidered.