Answer:
The answer is: d. Progesterone.
Explanation:
The menstrual cycle consists of a series of regular changes that naturally occur in the female reproductive system.
When the follicular phase begins, estrogen and progesterone levels are low. As a consequence, decomposition and shedding of the upper layers of the uterine lining, endometrium, and menstruation occurs.
The answer is: d. Progesterone.