In Bowlby's Formation of a Reciprocal Relationship Phase

In Bowlby's formation of a reciprocal relationship phase,

A) infants respond differently to a familiar caregiver than to a stranger, but do not protest when the familiar caregiver leaves.
B) babies approach, follow, and climb on a familiar caregiver in preference to others.
C) separation protest declines, and the child understands some factors that influence the caregiver's coming and going.
D) babies become upset when a familiar caregiver leaves.