Summary
The author concludes that total bank lending to companies is less today than it was five years ago. This is based on the following:
For large, financially strong companies, the current interest rates that banks pay to borrow are higher than the interest rates they can receive for loans to these companies.
Banks won’t lend to companies that are not financially strong.
Total lending by banks to small and medium companies is less today than it was five years ago.
Banks
For large, financially strong companies, the current interest rates that banks pay to borrow are higher than the interest rates they can receive for loans to these companies.
Banks won’t lend to companies that are not financially strong.
Total lending by banks to small and medium companies is less today than it was five years ago.
Banks
Missing Connection
The conclusion is that total lending is down from five years ago. We have a premise establishing that lending from small and medium companies is down from five years ago. But what about the large companies? Isn’t it possible that lending to large, financially strong companies actually increased in a way that offsets the decrease from small and medium companies?
So to make the argument valid, we want to learn that lending to large, financially strong companies has NOT increased enough to outweigh the decrease in lending to small/medium companies. The correct answer might interact with the first premise concerning interest rates for borrowing vs. lending concerning large companies. The role of that premise is not entirely clear right now.
So to make the argument valid, we want to learn that lending to large, financially strong companies has NOT increased enough to outweigh the decrease in lending to small/medium companies. The correct answer might interact with the first premise concerning interest rates for borrowing vs. lending concerning large companies. The role of that premise is not entirely clear right now.
A
Banks will not lend money at interest rates that are lower than the interest rates they pay to borrow.
The first premise tells us that the interest rates banks pay to borrow are higher than those they can get for loans to large, financially strong companies. (A), therefore, establishes that banks don’t currently lend to large, financially strong companies. If lending to small and medium has decreased, and banks currently don’t lend to large, then total lending must have decreased. 
B
Most small and medium-sized companies were financially stronger five years ago than they are now.
(B) leaves open the possibility that lending to large companies has increased.
C
Five years ago, some banks would lend to companies that were not financially strong.
(C) leaves open the possibility that lending to large companies has increased.
D
The interest rates that banks currently pay to borrow are higher than the rates they paid five years ago.
(D) leaves open the possibility that lending to large companies has increased.
E
The interest rates that small and medium-sized companies pay to borrow are higher than those paid by large, financially strong companies.
(E) compares the interest rates various companies pay to borrow. But this leaves open the possibility that lending to large companies has increased.
"Surprising" Phenomenon
Scientists began citing a smaller group of sources once they had easier access to a larger group of sources.
Objective
The right answer will be a hypothesis that explains why scientists ended up using a narrower range of sources after getting access to a larger range of sources. This explanation must account for some motivation or proclivity, be that general across disciplines or specific to the scientific community, to use less sources even when more sources are available. Alternatively, the explanation could account for some issue in the digitalized sources.
A
A few of the most authoritative scientific journals were among the first to offer full online access to their articles.
Even if the most authoritative journals were among the first to offer online access, the others eventually ended up online, as well. We need to know why scientists chose not to use these sources.
B
Scientists who wrote a lot of articles were the most enthusiastic about accessing journal articles online.
We’re not concerned about a subset of scientists. The correct answer will discuss scientists in general.
C
Scientists are more likely to cite articles by scientists that they know than they are to cite articles by scientists they have never met, even if the latter are more prominent.
If scientists generally cite people they know, then they probably aren’t citing the same articles as their peers at different institutions. This seems to contradict the stimulus rather than resolve it.
D
Several new scientific journals appeared at roughly the same time that full online access to scientific articles became commonplace.
A couple new scientific journals doesn’t change much. We don’t even know when these journals went online.
E
Online searching made it easier for scientists to identify the articles that present the most highly regarded views on an issue, which they prefer to cite.
Scientists can simply search for eminent articles rather than sifting through journals as before. These articles are generally preferred, so many scientists end up citing them. Thus, there’s less variety in the articles scientists choose to cite.
Summarize Argument: Phenomenon-Hypothesis
The author concludes that we should not conclude that volcanic activity caused the short-term spike in sulfur dioxide on Venus. This is based on the fact that no active volcanoes have been identified on Venus, and planetary atmospheres are known to undergo cyclical variations in chemical composition.
Notable Assumptions
The author assumes that inactive volcanoes could not have produced a short-term spike in sulfur dioxide on Venus. The author also assumes that there aren’t any active volcanoes that we haven’t identified on Venus that could have produced the spike. Another assumption is that the cyclical variations in chemical composition could have accounted for the spike in sulfur dioxide.
A
Conditions on Venus make it unlikely that any instrument targeting Venus would detect a volcanic eruption directly.
This suggests that there might be active volcanoes on Venus that we haven’t identified. If we can’t identify eruptions directly, that raises the possibility that our failure to identify active volcanoes doesn’t guarantee the absence of active volcanoes on Venus.
B
Evidence suggests that there was a short-term spike in sulfur dioxide in Venus’s atmosphere 30 years earlier.
It’s not clear what a short-term spike 30 years ago has to do with the short-term spike detected recently.
C
Levels of sulfur dioxide have been higher in Venus’s atmosphere than in Earth’s atmosphere over the long term.
We detected a short-term spike in sulfur dioxide on Venus. Comparative levels of sulfur dioxide on Venus and Earth don’t shed light on the cause of a short-term spike.
D
Traces of the sulfur dioxide from volcanic eruptions on Earth are detectable in the atmosphere years after the eruptions take place.
This suggests that traces of sulfur dioxide can last a long time from volcanoes. But this doesn’t explain a short-term spike in sulfur dioxide. We’re not just trying to explain the presence of sulfur dioxide in the atmosphere; we’re trying to explain a short-term spike.
E
Most instances of sulfur dioxide spikes in the Earth’s atmosphere are caused by the burning of fossil fuels.
If anything, this might strengthen the author’s argument by suggesting another explanation for the short-term spikes on Venus besides volcanoes.
All the apartments on 20th Avenue are in old houses. However, there are twice as many apartments on 20th Avenue as there are old houses. Therefore, most old houses on 20th Avenue contain more than one apartment.
Summarize Argument
The author concludes that most old houses on 20th Avenue contain more than one apartment. He supports this by saying that all the apartments are in old houses, and there are twice as many apartments as old houses.
Identify and Describe Flaw
The author concludes that most— i.e. more than half— of the old houses have more than one apartment, just because there are twice as many apartments as old houses. But let’s say there are 10 old houses and 20 apartments. What if one old house contains all 20 apartments? What if 4 old houses contain 5 apartments?
It’s not necessarily true that most of the old houses contain more than one apartment. In fact, it’s possible that most of the old houses don’t contain any apartments at all!
A
overlooks the possibility that some of the buildings on 20th Avenue are not old houses
The author doesn't overlook this possibility. He says that there are twice as many apartments as old houses and that all the apartments are in old houses. But there might still be other buildings that are not old houses.
B
draws a conclusion that simply restates one of the premises offered in support of the conclusion
This is the cookie-cutter flaw of circular reasoning, where the conclusion is simply a restatement of one of the premises. The author doesn’t make this mistake. His premises may not support his conclusion well, but they are distinct from his conclusion.
C
fails to consider the possibility that some buildings on 20th Avenue may offer types of rental accommodation other than apartments
The author doesn’t overlook this possibility. His argument is only about the old houses and apartments on 20th Ave. There might be some buildings that are hotels or rental houses, but this doesn’t affect his argument.
D
confuses a condition whose presence would be sufficient to ensure the truth of the argument’s conclusion with a condition whose presence is required in order for the conclusion to be true
This is the cookie-cutter flaw of confusing necessary and sufficient conditions. The author doesn’t make this mistake; he never presents a condition sufficient to ensure the truth of the conclusion in the first place.
E
fails to address the possibility that a significant number of old houses on 20th Avenue contain three or more apartments
If a significant number of old houses have 3 or more apartments, the author can't conclude that most houses have at least one. For example, if there are 10 old houses and 20 apartments, it's possible that just 4 houses have 5 apartments, meaning most houses have no apartments.
"Surprising" Phenomenon
Why do some land managers use a reforestation strategy that involves planting a single fast-growing tree species when their goal is to create an area with multiple tree species?
Objective
The right answer will be a hypothesis that either describes a benefit of the fast-growing-single-tree-species method or else a drawback of the seemingly obvious approach of planting multiple tree species.
A
Tree species that require abundant sunlight tend to grow quickly on degraded land.
This is irrelevant. Presumably, there are multiple tree species that require abundant sunlight to grow, so why wouldn’t land managers plant a variety of those species rather than just one fast-growing species?
B
An area with a multitude of thriving tree species tends to be more aesthetically pleasing than an area with only a single tree species.
This is irrelevant. We already know that the goal of reforestation is to create an area with a multitude of tree species, and we don’t need another reason why that’s a good thing to do. We just need to know how planting one fast-growing species helps achieve that goal.
C
The reforestation of degraded land is generally unsuccessful unless the land is planted with tree species that are native to the area designated for reforestation.
There are likely multiple tree species that are native to any given area, so why wouldn’t land managers just plant all those species rather than focusing on only one? We also don’t even know if the chosen fast-growing species are native to the degraded areas!
D
The growth of trees attracts wildlife whose activities contribute to the dispersal of a large variety of tree seeds from surrounding areas.
This explains why some land managers plant one fast-growing tree species! As those trees rapidly grow, wildlife come to the area, and with them they carry a large variety of tree seeds from nearby regions. Those seeds grow into trees and the goal of reforestation is complete!
E
The process of reforesting degraded sites is time consuming and labor intensive.
This is a blanket statement that doesn’t tell us anything that differentiates or explains distinct reforestation methods. Because we’re looking for an explanation of one specific reforestation method, this answer choice isn’t helpful.