hi, i took test 43 last friday, so i still have it fresh in my mind.
In B, the greatest possible number of larvae survive, but that is not what the beetles want- they will do whatever they can to minimize the number of the other beetles' larvae- it's a competetion. This choice doesn't really explain why they have given up trying to minimize the other beetles' populations. The beetles also don't want to adversely affect the size of their own broods. Maybe they would be cooperative like in B if the alternative adversely affected their own broods, but B doesn't give that information. The goal that B addresses- keeping the greatest number of larvae alive- is not the goal of the beetles and so does not resolve the paradox.
E could be true, but does not at all resolve the paradox; it only adds to it. If breeding sites can only accomodate a limited number of larvae, then the competition among beetles makes sense and the cooperation is puzzling. You might think E explains the contradiction in the following way: if the breeding sites can only accomodate a limited number of larvae, then that would explain why the beetles destroy each others eggs; they destroy the eggs so that, when the eggs hatch, there aren't too many larvae for the limited space. this reasoning is flawed, however, because we already know why the beetles destroy the eggs- they want to minimize the size of their competitors' broods. E doesn't explain why they would stop trying to do this once the eggs hatch.
i hope that helps. good luck!