Hi Asch,
I hear you man, RC is also my worst topic. Thanks for posting this passage, it's a tough one!
Here's my take on answer explanations:
#161
The question is asking for a variable that Jarvis believes may not influence naked mole rat behavior. Jarvis found that growth rates do influence behavior, so option D is the opposite of what we are looking for. Jarvis says that behavior (length of time a mole rat performs a certain task) is not influenced by age, so B is the answer.
#166
A - no conclusions are stated in paragraph 3. The conclusion is at the end of paragraph 1, and states that an altruistic vertebrate society may exist, that being the naked mole rat.
B - "Contradict" is a very strong word. Paragraph 4 discusses cooperatively breeding vertebrates that differ from mole rats in their behavior, but none of this information contradicts anything in paragraph 3. This can't be the answer unless the passage explicitly states something like "X causes Y" in paragraph 3, followed by "X cannot cause Y" in paragraph 4.
C - Paragraph 2 discussed only similarities between mole rats and cooperatively breeding insects. Paragraph 3 defines a limit to the similarities between mole rats and cooperatively breeding insects by introducing differences between them. There could be other similarities between mole rats and cooperatively breeding insects that are not mentioned in the passage, and these similarities would alter the extent to which the two groups are similar. However, as a general rule on the GMAT, we should avoid considering all outside information. As far as answering questions is concerned, all similarities between the mole rats and cooperatively breeding insects are contained within the passage, and paragraph 3 puts a limit on the similarities by beginning to introduce differences.
D - The "specific study" must be Jarvis' work because it is the only specific study mentioned in the entire passage. However, Jarvis' work is not a conclusion but just one of several indications of factors that influence mole rat behavior.
E - What are the three explanatory factors? The first is reproductive status, which the paragraph states to be the most important explanatory factor in mole rat behavior. The second is body size. The text gives examples of different behaviors that are characteristic of mole rats with small and large body size, so body size is also an explanatory factor. The third factor is age, which the passage indicates via Jarvis' work as a factor that does not influence the task a mole rat performs. Thus, the passage has ranked these three factors in terms of their effect on behavior. No two of them can be considered of equal significance.