Harlow and Colleagues' Studies with Infant Rhesus Monkeys Reared in Isolation

Harlow and colleagues' studies with infant rhesus monkeys reared in isolation demonstrated that, compared to monkeys reared normally with their mothers, those reared in isolation and then placed with other monkeys:

A) were socially isolated.
B) were incapable of caring for their own young.
C) were unable to communicate effectively with other monkeys.
D) were socially isolated, unable to communicate with other monkeys, and incapable of caring for their young.