Identify the correct statement from the following:

1. High levels of oestrogen increases the surge of LH and FSH which in turn leads to ovulation.

2. Oogonial cells are added in the foetal stage only and not after the birth.

3. The sperms become highly motile and fertile in the head of the epididymis. They are not highly motile when they are released from the seminiferous tubules.

4. The ruptured follicle closes after the release of egg and leads to the formation of corpus luteum. This corpus luteum produces progesterone. Hence the progesterone level is high during the post ovulatory phase of menstrual cycle.

Therefore, only option ‘d ’is correct.