Studies on Infants' Recognition of Their Mothers Show That

Studies on infants' recognition of their mothers show that

A) infants recognize their mother's face for the first time when they are about 4 months old.
B) infants can recognize their mother's face and voice before they reach the age of 1 week.
C) it is so difficult to test infants' memory that we cannot test infants' face or voice recognition until they are about 2 months of age.
D) infants' perceptual skills are so limited that they cannot recognize either the face or the voice of their mother until 6 months of age.