A
Most species with black-and-white coloration are more populous than the species that prey upon them.
B
No form of camouflage is completely effective against all kinds of predators.
C
Animals of many predatory species do not perceive color or pattern in the same manner as humans do.
D
Conspicuous black-and-white areas help animals of the same species avoid encounters with one another.
E
Black-and-white coloration is not as great a liability against predators at night as it is during the day.
Extracurricular
Philosopher: A person is morally responsible for an action only if that action is performed freely. And an action is free only if there is an alternative action that is genuinely open to the person. But an alternative action is genuinely open only if performing that alternative action is not morally wrong.
Summary
The stimulus can be diagrammed as follows:
Notable Valid Inferences
If someone is morally responsible for an action, then it is not the case that the alternative to that action is morally wrong.
If an action was performed freely, then it is not the case that the alternative to that action is morally wrong.
If someone is morally responsible for an action, then there is an alternative action that is genuinely open to the person.
A
An alternative action is not genuinely open to a person unless that person would be morally responsible for performing the alternative action.
Could be false. We know that moral responsibility is a sufficient condition for an alternative action being genuinely open; (A) mixes up the sufficient and necessary conditions of this relationship.
B
People are not morally responsible for most of the actions that they perform.
Could be false. The stimulus does not discuss any quantities; we cannot make any inferences about “most” actions that people perform.
C
A person is morally responsible for an action if there is an alternative action that is genuinely open to the person.
Could be false. We know that moral responsibility is a sufficient condition for an alternative action being genuinely open. Like (A), (C) mixes up the sufficient and necessary conditions of this relationship.
D
If it would be morally wrong for a person to perform a given action, then that action is genuinely open to that person.
Could be false. We know that if an alternative action is morally wrong, then that alternative action was not genuinely open. (D) misses the fact that this relationship discusses “alternative” actions. Also, the necessary condition is that the action is not genuinely open.
E
An action is not free unless there is an alternative action that is not morally wrong.
Must be true. As shown below, an action being performed freely is a sufficient condition for the alternative to that action not being morally wrong.
A
The likelihood of becoming overweight depends not only on how many calories one consumes but also on how rapidly one burns those calories through physical activity.
B
Due to the fact that nuts are rich in calories, consuming a sufficiently large quantity produces a feeling of satiation.
C
If people who avoid a certain kind of food are more likely to be overweight than people who consume that food regularly, then that food should not be avoided for weight loss purposes.
D
On average, people who never eat nuts consume the same total calories per day as people who regularly eat nuts.
E
Most people who regularly eat nuts eat correspondingly less of foods whose taste, unlike that of nuts, stimulates a hunger response.
A
Increases in produce prices are largely driven by increases in the fuel costs of bringing crops to market.
B
The average personal garden is much smaller than it was decades ago when inexpensive produce started to become available.
C
Community gardens report that waiting lists for renting garden plots have gotten longer over the last year.
D
Personal gardens are usually popular in economic downturns.
E
A large retail seed company went out of business early last year.
A
It compares the incidence of back injury between two groups who probably do not have the same risk factors for back injury.
B
It fails to address the possibility that Flegco Corporation employees are more likely to wear back belts than are employees who perform similar tasks in other corporations.
C
It takes for granted that if a factor is associated with an increased likelihood of a certain effect, that factor must causally contribute to that effect.
D
It confuses the claim that a phenomenon does not causally contribute to a certain effect with the claim that that phenomenon causally contributes to preventing that effect.
E
It fails to address the possibility that even if a factor is sufficient to produce a certain effect, its presence may not be necessary in order for that effect to be produced.