Juvenile monkeys that are separated from their mothers will often show self-destructive behavior, such as picking at their fur or refusing to eat. These behaviors are the most prevalent in monkeys that are caged alone, are somewhat less prevalent when the monkeys are caged with other, unrelated juveniles and adult males, and are the least prevalent, but still observable, when the monkeys are caged with a mixed-gender group of unrelated, adult monkeys.

Which of the following hypotheses best explains the phenomenon described above?

(A) The presence of unrelated juvenile and adult male monkeys causes more self-destructive behavior in juvenile monkeys than does the presence of a mixed-gender group of unrelated adult monkeys.

(B) The presence of unrelated adult female monkeys is more important to juvenile monkeys in alleviating distress caused by being separated from their mothers than is the presence of unrelated juvenile monkeys.

(C) The presence of unrelated adult male monkeys is threatening to juvenile monkeys, causing self-destructive behavior similar to that caused by the separation of juvenile monkeys from their mothers.

(D) The presence of unrelated adult female monkeys serves as a suitable substitute for a juvenile monkey’s mother following a separation from the mother.

(E) Juvenile monkeys that display self-destructive behavior will engage in this behavior the least when reunited with their mothers, and will engage in this behavior slightly more when caged with adult female monkeys who are not their mothers.

IMO B.

A: The presence of unrelated juvenile and adult male monkeys causes more self-destructive behavior in juvenile monkeys than does the presence of a mixed-gender group of unrelated adult monkeys.This option says the presence causes self-destructive behavior but it is the separation from the mother that causes this behavior.
B: The presence of unrelated adult female monkeys is more important to juvenile monkeys in alleviating distress caused by being separated from their mothers than is the presence of unrelated juvenile monkeys.This option rightly says that the presence of other adult female monkeys helps in alleviating the distress caused by separation from mother.
C: The presence of unrelated adult male monkeys is threatening to juvenile monkeys, causing self-destructive behavior similar to that caused by the separation of juvenile monkeys from their mothers.Nothing in the passage suggests that the presence of adult male monkeys is threatening to juvenile monkeys.
D: The presence of unrelated adult female monkeys serves as a suitable substitute for a juvenile monkey’s mother following a separation from the mother.The presence is not a substitute because self-destructive behavior is not completely absent but it is at its least when adult female monkeys are present.
F: Juvenile monkeys that display self-destructive behavior will engage in this behavior the least when reunited with their mothers, and will engage in this behavior slightly more when caged with adult female monkeys who are not their mothers. This option is too definitive. It says that the juvenile monkeys WILL display self-destructive behavior even after reuniting with their mothers.

OFFICIAL EXPLANATION

The question stem presents a series of premises about how juvenile monkeys behave when separated from their mothers; specifically, the behaviors are more or less prevalent under various conditions. We are asked for the hypothesis that would best explain the variations in behavior. Although we are not asked to draw a conclusion from the premises, we should look for an explanatory hypothesis using the same constraints: assume as little as possible and take no unnecessary logical leaps.

(A) This choice confuses alleviation of self-destructive behavior with causation of that behavior. The question stem attributes the behavior to separation from the mother, not to the presence of other monkeys.

(B) Correct. We are told that separation from the mother causes self-destructive behavior that is lessened some in the presence of other, unrelated juveniles and adult males, and lessened even more in the presence of a mixed group of unrelated, adult monkeys. Since adult male monkeys are present in both cases, they may be disregarded as a cause of the difference in degree of self-destructive behavior. The best hypothesis is that the distressed juveniles are more comforted by the adult females than by the other juveniles.

(C) We have no reason to believe that any other monkeys are “threatening”—merely that some monkeys alleviate distress better than others.

(D) This choice is on the right track, but its language is too strong. We know that the presence of unrelated adult female monkeys is more soothing than the presence of other monkeys to a juvenile that has been separated from its mother, but we don’t know if the juveniles are comforted to such a degree that the unrelated females are a “suitable substitute.” (For instance, perhaps the presence of other juveniles alleviates the behavior by 5%, and the presence of the unrelated females by 10%).

(E) The situation described does not mention reuniting monkeys with their mothers. Stay away from choices that require making additional, unnecessary assumptions.
_________________

"Be challenged at EVERY MOMENT."

“Strength doesn’t come from what you can do. It comes from overcoming the things you once thought you couldn’t.”

"Each stage of the journey is crucial to attaining new heights of knowledge."

Rules for posting in verbal forum | Please DO NOT post short answer in your post!

Advanced Search : https://gmatclub.com/forum/advanced-search/