Evolutionary Theorists explain the Early Separation Protests of Infants from Many

Evolutionary theorists explain the early separation protests of infants from many nonindustrialized societies by claiming that

A) these infants have learned that their needs are unlikely to be met in the caregiver's absence
B) separations from caregivers are highly unusual and, thus, fear-provoking events
C) these infants have no idea where caregivers are going or when they will return
D) all of these