The shedding of the endometrium in the menses phase is triggered by:
a. Declining levels of progesterone
b. Fluctuating levels of estrogen
c. Surges of luteinizing hormone
d. Degeneration of the myometrium
a. Declining levels of progesterone
b. Fluctuating levels of estrogen
c. Surges of luteinizing hormone
d. Degeneration of the myometrium