Assertion : Corpus luteum is present in proliferative phase of menstrual cycle .
Reason : High concentration of progesterone is present in
proliferative phase .

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

To solve the question, we need to analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Corpus luteum is present in the proliferative phase of the menstrual cycle."
- The corpus luteum is a structure that forms in the ovary after ovulation, which occurs during the luteal phase of the menstrual cycle, not the proliferative phase.

2. **Understanding the Reason**:
- The reason states that "High concentration of progesterone is present in the proliferative phase."
- Progesterone is primarily produced by the corpus luteum, which is active during the luteal phase, leading to a high concentration of progesterone during this phase. Therefore, the statement about high progesterone levels in the proliferative phase is incorrect.

3. **Conclusion**:
- Since the assertion is incorrect (the corpus luteum is not present in the proliferative phase) and the reason is also incorrect (high progesterone concentration is not present in the proliferative phase), we can conclude that both the assertion and the reason are false.

4. **Final Answer**:
- Therefore, the correct answer is option D: both assertion and reason are false.