This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
Apoptosis can occur by change in hormone levels in the ovarian cycle. When there is no fertilization of the ovum, the endometrial cells die because: 
Select and explain. 
A. The involution of corpus luteum causes estradiol and progesterone levels to fall dramatically, B. LH levels rise after ovulation, C. Estradiol levels are not involved in the LH surge phenomenon, D. Estradiol inhibits the induction of the progesterone receptor in the endometrium
A: The involution of corpus luteum causes estradiol and progesterone levels to fall dramatically
Answer: A: The involution of corpus luteum causes estradiol and progesterone levels to fall dramatically 
Explanation: None