Which process is responsible for causing menstruation?

Option A is correct

Explanation:

Complete question

Which process is responsible for causing menstruation? a. breakdown of the corpus luteum b. fertilization of the egg c. implantation of the egg in the endometrium d rupture of a follicle in the ovary e. repair of the endometrial lining

Solution

Menstruation is triggered by reduced level of estrogen and progesterone which usually happens in the luteal phase of the menstrual cycle. When the uterus wall with new lining (endometrium) do not receive fertilized egg for implantation, the corpus luteum breaks down and later the endometrium also starts to break down which is eventually sloughed off leading to next menstruation period.  

Hence, option A  is correct