Hi
@strong oak -
In general, for a question like this, you're going to want to pick an answer that directly contradicts or undermines something stated in the passage. The key assertion here is "such is the animal function of intelligence" -- although we then have to figure out what "such" refers to. By going up to the previous sentence, we can identify that the "animal" function refers to instrumental reasoning that serves one's own interests. This is further supported by the analogy that the author makes between "animals making humans possible" and "conquerors preparing the way for poets." Therefore, if nonhuman animals were to behave altruistically, that would undermine the point the author is making about animal intelligence -- making C the correct answer.
B is a little bit trickier. Overall, the author seems to be praising aggressiveness -- although the author does suggest that the human ideal doesn't include the aggressiveness that allowed us to evolve into cognitively sophisticated beings, the author also describes how that same "human ideal" exemplified by philosophers and poets sets the stage for its own destruction. The author might argue about at which stages of civilization aggression tends to be admired, but would overall approve of aggression (and in fact, the author seems to admire aggressiveness him/herself!) So B doesn't directly undermine the author's argument in a direct way, unlike C.
Hope this helps & best of luck studying!!
