Assertion : Sclerenchyma cells do not have plasmodesmata.
Reason : The cell walls of some permanent tissues are heavily lignified.

Options

A. (a) If both Assertion and Reason are true and the Reason is the correct explanatin of the Assertion.
B. (b) If both Assertion and Reason are true, but the Reason is not the correct explanation of the Assertion.
C. (c) If Assertion is true, Reason is false.
D. (d) If both Assertion and Reason are true.

Answer

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

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Sclerenchyma cells do not have plasmodesmata."
- **Truth Value**: This statement is true. Sclerenchyma cells are known for their thick, lignified cell walls, which do not contain plasmodesmata. Plasmodesmata are channels that allow for communication and transport between adjacent plant cells, but sclerenchyma cells are specialized for structural support and do not require these connections.

2. **Understanding the Reason**:
- The reason states that "The cell walls of some permanent tissues are heavily lignified."
- **Truth Value**: This statement is also true. Sclerenchyma is a type of permanent tissue characterized by its heavily lignified cell walls, which contribute to the mechanical strength of the plant.

3. **Connecting the Assertion and Reason**:
- The reason explains why the assertion is true. The heavy lignification of sclerenchyma cell walls makes them impermeable and eliminates the need for plasmodesmata, which are typically involved in cell-to-cell communication and transport.

4. **Conclusion**:
- Both the assertion and the reason are true, and the reason correctly explains the assertion. Therefore, the correct answer is that both the assertion and reason are true, and the reason is the correct explanation of the assertion.

### Final Answer:
Both the assertion and reason are true, and the reason is the correct explanation of the assertion.