Recent studies found that a disorganized attachment style developed in infancy only when infants had the short version of the serotonin transporter gene, 5-HTTLPR. This gene-environment interaction only occurred when
A. The infants' other consciousness developed poorly in the first six months after birth.
B. Mothers showed a low level of responsiveness toward their infants.
C. Maternal nutrition was deficient during the prenatal period.
D. The infants were temperamentally inclined toward negative affectivity.