Ancient Anthropoids Began to Have Fewer Offspring That Required Longer

Ancient anthropoids began to have fewer offspring that required longer and more attentive care. What did this select for?

A) a greater reliance on nuts and tubers
B) pair bonding, which resembles the nuclear family, among 90 percent of present-day anthropoids
C) increased reliance on life in trees, which protected the young from predators
D) a greater capacity for brachiation
E) increased social complexity