Assertion :- Primary wall constituent of the cell wall is not of persistent nature.
Reason:- Primary wall gradually diminishes as the cell matures and the secondary wall is formed on inner side.

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 Text Solution:

1. **Understanding the Assertion**: The assertion states that the primary wall constituent of the cell wall is not of persistent nature. This means that the primary cell wall does not remain unchanged throughout the life of the cell.

2. **Understanding the Reason**: The reason provided explains that the primary wall diminishes as the cell matures and that a secondary wall is formed on the inner side. This indicates a developmental process where the primary wall is replaced or diminished as the cell undergoes maturation.

3. **Analyzing the Relationship**: The assertion and reason are closely related. The reason explains why the assertion is true. As the cell matures, the primary wall is indeed replaced by the secondary wall, which is more robust and persistent.

4. **Conclusion**: Since both the assertion and reason are true, and the reason provides a correct explanation for the assertion, we can conclude that the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

5. **Final Answer**: The correct answer is option 1: Both assertion and reason are true, and the reason is the correct explanation of the assertion.