Critical Reasoning

The prairie vole, a small North American grassland rodent, breeds year-round, and a group of voles living together consists primarily of an extended family, often including two or more litters. Voles commonly live in large groups from late autumn through winter; from spring through early autumn, however, most voles live in far smaller groups. The seasonal variation in group size can probably be explained by a seasonal variation in mortality among young voles.

Which of the following, if true, provides the strongest support for the explanation offered?

A. It is in the spring and early summer that prairie vole communities generally contain the highest proportion of young voles.
B. Prairie vole populations vary dramatically in size from year to year.
C. The prairie vole subsists primarily on broad-leaved plants that are abundant only in spring.
D. Winters in the prairie voles' habitat are often harsh, with temperatures that drop well below freezing.
E. Snakes, a major predator of young prairie voles, are active only from spring through early autumn.

OA after some discussion.

IMO E.

Conc: Many young voles die in spring through autumn.

A. Contradicts the conc. Weakens.
B. Irrelevant
C. No relevance to young voles
D. Irrelevant
E. Supports the conclusion.

[quote="sam2304"]IMO E.

Conc: Many young voles die in spring through autumn.

A. Contradicts the conc. Weakens.
B. Irrelevant
C. No relevance to young voles
D. Irrelevant
E. Supports the conclusion.[/quote]

Why not C? As the said plants on which Prairie vole (whether adult or young - not mentioned) is abundant only in summer and therefore they live in smaller groups to get greater proportion of food, i.e., plants.

Where I am wrong?

ranjeet75 wrote:
Why not C? As the said plants on which Prairie vole (whether adult or young - not mentioned) is abundant only in summer and therefore they live in smaller groups to get greater proportion of food, i.e., plants.

Where I am wrong?

Does it really matter to live in smaller groups to get greater proportion of food when there is abundance of the same.
They could have gathered and stored more food if they were part of a larger group (though this is based on a simple logic - the more in number, the more powerful ).
The above questions make the choice C, a bit confusing, or might even tempt us go a bit out of scope also. This does not happen with Choice E, which is much more clearer and straightforward.

It is definitely E. The only reason that ties to "Mortality rates" directly and in the same season.

Clearly E.

Please confirm OA.

A case can be made for (D) too. Winter is harsh so by the time summer comes most die;

ranjeet75 wrote:

sam2304 wrote:IMO E.

Conc: Many young voles die in spring through autumn.

A. Contradicts the conc. Weakens.
B. Irrelevant
C. No relevance to young voles
D. Irrelevant
E. Supports the conclusion.

Why not C? As the said plants on which Prairie vole (whether adult or young - not mentioned) is abundant only in summer and therefore they live in smaller groups to get greater proportion of food, i.e., plants.

Where I am wrong?

E is better compared to C. Its more straightforward linking to the mortality rates of young voles.