Confusing CR from GMATPREP

At first, none of the answer choices seem to be correct. Indeed, a crazy question. I'm not sure that my answer and reasoning are correct.

I'll go with B

The stem wants us to select an answer choice that would help us in evaluating whether the tranquilizer inhibits fertility

a) The fact that there are more collared female rhinos than uncollared ones( or even if it is the other way around) does not help us in evaluating whether the tranquilizer is causing infertility
b) Since all the rhinos are mammals and all the mammals typically respond in a similar fashion to a tranquilizer( I'm assuming this), I would be curious to know how the tranquilizer used in rhinos is different from the one used in other mammals. If it is different, then there is a possibility that the it is causing infertitlity
c) Even if the rangers use the tranquilizer 100 times every day, it would not help in evaluating the argument. We need some pointers that can help us in making sense between tranquilizer and fertility
d) This is not at all concerned with the argument
e) Whether or not radio collars are the practical means to track their motion will definitely not help the case at hand

Cheers,
Unplugged