The correct option is B To shed enlarged endometrium layer which is not needed
Menstruation is a woman's monthly bleeding. It occurs so as to shed the lining of the uterus or womb.
In menstrual cycle, the uterus gets prepared for implantation and the endometrium builds up, After ovulation, if the egg released does not gets implanted in the uterus, it leads to shedding off this endometrium and its lining and this is called as menstruation,
Thus, the correct answer is option B.