Which Has Not Been Observed in Cross-Cultural Research of Infant

Which has not been observed in cross-cultural research of infant emotional development and attachment?

A) Differences in the structure of childcare arrangements
B) Differences in parents' views and expectations around appropriate infant and child behaviors
C) Differences in whether infants actually form an attachment with their caregivers
D) Differences in infants' experiences of being separated from primary caregivers
E) Differences in infants' experiences interacting with strangers