Monkeys raised without mothers in captivity

a. displayed normal sexual behavior

b. did not know how to care for infants

c. were able to form lasting affectional ties

d. showed greater sexual dimorphism than those in the wild

b. did not know how to care for infants

Explanation:

Research shows that captive-bred monkeys without their mothers don't know how to care for babies. This is because these little monkeys grow up without maternal support, do not have a behavioral model about caring for babies and therefore can not create enough affective bond to care for their infants. Monkeys are very intelligent beings and often associate the behavior of other monkeys as inspiration for the situations they are facing, captive-bred monkeys without their mothers do not have this model of inspiration and therefore do not know how to take care of baby monkeys.