PT 2, Oct 1991, Sec 2, #21

Ambitious

Hello,

I don't understand why D is the correct answer. I chose C. Could someone please explain why the right answer is right and the wrong answers are wrong? Thank you

nye8870

About 50 million years ago: Bears/Raccoons/Giant Pandas/Red Pandas/Coatis were all one species.
About 30 million years ago: Bears and Raccoons split from one another. (At this point we do not know how or which lineage the Pandas will follow).
20 million years ago: Red Pandas split off from Raccoons/Coatis.
10 million years later: Giant Pandas split off from bears.
Based on the stimulus saying, “The more genetically similar two species are to each other, the more recently they diverged (split off)”, it must be true that Giant Pandas are closer related genetically to bears (which happened only 10 million years ago) than to raccoons, which happened around 30 million years ago. That is ac(D).
(A) We don’t know what scientists originally thought…must eliminate.
(B) Eighth species of bear? Who ever said that? Eliminate.
(C) Within a margin of a few years? (millions of years is not a few) Eliminate.
(E) The stim does not really inform us on how much/many scientists agree about this. And even if there is consensus the facts do not support what (E) is asserting (because: Red Pandas are closer related - not equally– there is a 10 million year difference in split-time).