Progesterone puill helps in preventing pergnancy by allowing

Options

A. ova formation
B. fertilisation
C. implantation
D. None of these

Explanation

### Step-by-Step Solution:

1. **Understanding Progesterone**: Progesterone is a hormone that plays a crucial role in the female reproductive system. It is primarily involved in regulating the menstrual cycle and maintaining pregnancy.

2. **Mechanism of Action**: The primary function of progesterone in the context of preventing pregnancy is to inhibit ovulation. Ovulation is the process where an ovary releases an egg (ovum) for potential fertilization.

3. **Follicular Development**: Progesterone reduces the development of ovarian follicles. Follicles are fluid-filled sacs in the ovaries that contain immature eggs. By inhibiting the growth of these follicles, progesterone prevents the release of an egg.

4. **Prevention of Ovulation**: Since progesterone reduces follicular development, it effectively prevents ovulation. Without ovulation, there is no egg available for fertilization by sperm.

5. **Fertilization and Implantation**: If there is no ovum released, fertilization cannot occur. Additionally, without fertilization, there is no implantation of a fertilized egg in the uterus.

6. **Conclusion**: Therefore, the statement in the question that "progesterone pill helps in preventing pregnancy by allowing" is incorrect. The correct understanding is that progesterone prevents pregnancy by inhibiting ovum formation, fertilization, and implantation.

7. **Final Answer**: The answer to the question is "none of these" because the progesterone pill does not allow ovum formation, fertilization, or implantation; it prevents them.