The argument tells us that a chimp who displays feelings of affection is more likely to be defended by its group members. This shows that, from a sociological perspective, affection plays the same role in chimp communities as in human, since humans are more willing to face risks to protect those toward whom they have feelings of affection. Notice the important distinction - in human communities, humans are more likely to protect those for whom THEY have feelings of affection, whereas in chimp communities we only have evidence that chimps are more likely to protect those who display feelings of affection TOWARD THEM. The argument's conclusion that affection plays the same role requires us to either assume that humans are also more likely to protect those who display affection TOWARD THEM or chimps are likely to protect those who THEY feel affection for. The correct answer choice reflects the second assumption and confirms that since feelings of affection are at least sometimes reciprocated, chimps may have feelings of affection toward chimps that display affection toward them, and protect them, similar to the human behavior.