In the last few weeks of pregnancy, the level of estrogen in the woman’s blood rises. This increase causes

a. the amount of prostaglandins secreted by the placenta to decrease.
b. the muscles of the uterus to become more sensitive to the hormone oxytocin.
c. even more estrogen to be released from the pituitary gland.
d. the fetus to develop more rapidly.

b. the muscles of the uterus to become more sensitive to the hormone oxytocin.