According to a Review of the Research on Responsiveness to Infants

According to a review of the research on responsiveness to infants, the strongest evidence for a gender difference comes from studies

A) in which girls and boys have been secretly observed playing with dolls.
B) in which college men and women have been observed interacting with babies.
C) in which self-reports of behavior are used as the measurement of responsiveness rather than behavioral observations or physiological measures.
D) that have used both men and women.