Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information. A. Only monkeys that have learned to control their selfish and aggressive behaviors can be involved in social groups. B. Selfish and aggressive animals like monkeys live in groups in order to practice appropriate social behaviors. C. Monkeys and other social animals need to learn behaviors appropriate for their social groups. D. Some monkeys are naturally too selfish and aggressive to understand the give-and-take of social groups, so they learn such important behaviors while young.