During Parturition A Positive Feedback Mechanism Occurs When Stimulat

During parturition, a positive-feedback mechanism occurs when __________ stimulates the secretion of __________ , which results in uterine contractions.

A)                       progesterone, estrogen

B)                       estrogen, progesterone

C)                       estrogen, oxytocin

D)                       oxytocin, estrogen

E)                       uterine stretch, oxytocin