Lactation Normally Does Not Occur During Pregnancy Because

Lactation normally does not occur during pregnancy because

A) the breast ducts do not develop until after a baby is born.
B) the high levels of estrogen and progesterone in maternal plasma inhibit prolactin effects on the breasts.
C) maternal plasma levels of prolactin are low during pregnancy.
D) high levels of androgens inhibit milk synthesis by the breasts.
E) the low levels of circulating estrogen and progesterone during pregnancy inhibit milk synthesis by the breasts.