Assertion : During follicular phase , the primary follicles in the ovary grow to become a fully mature Graafian follicle .
Reason : Endometrium of uterus regenerates during follicular phase due to increasing level of progesterone .

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion .
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False .
D. If both Assertion & Reason are False.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that during the follicular phase, primary follicles in the ovary grow to become a fully mature Graafian follicle.
- This is indeed correct. The follicular phase is characterized by the maturation of follicles, where primary follicles develop into Graafian follicles, which are ready for ovulation.

2. **Understanding the Reason**:
- The reason provided states that the endometrium of the uterus regenerates during the follicular phase due to increasing levels of progesterone.
- This statement is partially correct in that the endometrium does regenerate, but the key point is that this regeneration is primarily influenced by estrogen, not progesterone. Progesterone plays a role later, during the luteal phase, where it helps maintain the endometrium after ovulation.

3. **Conclusion**:
- Since the assertion is true and the reason is false, we can conclude that the assertion is correct while the reason is incorrect.

### Final Answer:
- **Assertion**: True
- **Reason**: False