Assertion: TMV is a virus which causes mosaic disease.
Reason: TMV has RNA as genetic material.

Options

A. Assertion is correct, reason is correct, reason is a correct explanation for assertion.
B. Assertion is correct, reason is correct, reason is not a correct explanation for assertion
C. Assertion is correct, reason is incorrect
D. Assertion is incorrect, reason is correct.

Explanation

To solve the question regarding the assertion and reason about TMV (Tobacco Mosaic Virus), we will analyze both statements step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "TMV is a virus which causes mosaic disease."
- TMV is indeed a virus that infects tobacco plants and causes a disease characterized by a mosaic pattern on the leaves. This is a well-established fact in plant pathology.

2. **Understanding the Reason**:
- The reason states that "TMV has RNA as genetic material."
- TMV is known to have single-stranded RNA as its genetic material. This is also a scientifically accurate statement.

3. **Evaluating the Truth of Each Statement**:
- Both the assertion and the reason are true.
- Assertion: True (TMV causes mosaic disease).
- Reason: True (TMV has RNA as genetic material).

4. **Determining if the Reason Explains the Assertion**:
- While both statements are true, the reason does not explain why TMV causes mosaic disease. The presence of RNA as genetic material does not directly relate to the symptoms of the disease (mosaic pattern) observed in infected plants.

5. **Conclusion**:
- The assertion is true, the reason is true, but the reason does not provide a correct explanation for the assertion.
- Therefore, the correct conclusion is that both the assertion and reason are true, but the reason is not a correct explanation of the assertion.

### Final Answer:
- Assertion: True
- Reason: True
- Explanation: The reason does not explain the assertion.