In a study of tropical forests it was found that while the species of trees that is most common in a particular fores...

Irina on October 22, 2019

@zgnewquist,

The correct answer choice is (E), please let us know if you are seeing a different answer.

filozinni on June 6, 2020

Could you please explain why E is a better answer than A or B? Thank you!

Emil-Kunkin on November 14 at 03:27PM

The tension we need to resolve here is that trees of rarer species tend to live longer than those of common species. This seems weird, so we need to find a reason why that is.

E does give us a possible reason. The common trees are competing more for the same resources, so while there may be more of them, they might not live as long due to the fierce competition. Rarer trees, however, do not face such competition, which enables them to live longer.

A doesn't resolve this tension, if anything it makes it harder to explain because one would expect the trees best adapted to the climate to live longer.

B looks quite tempting, but it confuses the frame of reference. The passage tells us that trees of one species tend to live longer than trees of another. B is just telling us that as any tree ages, it will reproduce less frequently. This doesn't explain the disparity between the two species.