After ovulation graafian follicle regresses into which of the following?

Corpus Luteum.

The correct answer is Option (1) – Corpus Luteum.

After ovulation, the Graafian follicle regresses into the corpus luteum.

The corpus luteum is a temporary endocrine structure that forms from the remnants of the ovarian follicle after ovulation. It plays a crucial role in the menstrual cycle and early pregnancy by secreting progesterone, which helps maintain the uterine lining and supports early pregnancy. Such an endometrium is necessary for implantation of the fertilised ovum and other events of pregnancy. During pregnancy all events of the menstrual cycle stop and there is no menstruation. In the absence of fertilisation, the corpus luteum degenerates. This causes disintegration of the endometrium leading to menstruation, marking a new cycle.

So, the correct answer is: Corpus Luteum.