The correct option is D estrogen
The endometrium of the uterus rebuilds after menstruation under the influence of estrogen hormone secreted by the follicles of the ovary.
Relaxin, as the name suggests, relaxes the ligaments in the pelvis, widens the cervix and thus facilitates childbirth.
Oxytocin induces strong contractions in the uterus and helps in childbirth. It is also responsible for the release of milk after parturition.
Progesterone maintains the endometrium which is essential for pregnancy.