Zoologist: Meerkats are desert mammals that live in groups

The zoologist believes that because all meerkats stand equal chance of being killed by predators during the time when the group is foraging for food, the guard does not do any unselfish (altruistic) work for the other meerkats. so to prove zoologist wrong and to prove that the meerkat who stands as guard does indeed works with unselfish motives we have to show a act which meerkat who stands as guard does without any selfish purpose. E does the job.

E proves that the meerkat who does the job of standing as guard and forgoes foraging may not have any chance of eating because other members of group may not share food with him or her. With this external premise, add the original premise which says that the meerkat who stands as guard has equal chance of getting killed while the group is foraging . From both we infer that meerkats motives may indeed be altruistic as one who stands as guard may not gain any food from foraging activity but still risks his life equally as others. so the only ones who may be gaining anything are the group members who are involved in foraging and the one who stands as guard has nothing to gain but something to lose( risk of losing life)


B ) Does indeed questions the faulty criteria zoologist uses to determine the meerkats behaviour in general based on only 1 reason (that all stand equal chance of getting killed and not just the guard, so the guard is not doing any unselfish work). This choice only questions the faulty criteria that author uses to question the meerkats behaviour BUT choice E proves the zoologist's conclusion itself as wrong and establishes the fact that meerkats behaviour may indeed be altruistic.

Other answers are pretty weak and do not weaken or address the the conclusion.