Which Statement About Infants' Emotional Development Is True

Which statement about infants' emotional development is true?

A) The social smile in response to another person first appears at about 12 weeks old.
B) Very young infants seem incapable of expressing distress and contentment.
C) A 5-month-old baby is likely to display fear of strangers and separation anxiety.
D) An 11-month-old baby may show separation anxiety when her mother goes into another room.