Assertion : Penicillium yields penicillin.
Reason : Penicillium causes soft rot disease of citrus fruits.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false.
D. If both assertion and reason are false.

Explanation

To solve the assertion and reason question regarding Penicillium and its relationship to penicillin and citrus fruit diseases, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Identify the Assertion**:
- The assertion states that "Penicillium yields penicillin."
- This is true because Penicillium is a type of mold from which the antibiotic penicillin is derived.

2. **Identify the Reason**:
- The reason states that "Penicillium causes soft rot disease of citrus fruits."
- This is also true. Certain species of Penicillium, such as Penicillium italicum and Penicillium digitatum, are known to cause soft rot in citrus fruits.

3. **Evaluate the Relationship**:
- While both the assertion and the reason are correct, the reason does not explain the assertion. The assertion is about the production of penicillin, while the reason discusses a disease caused by some species of Penicillium.

4. **Conclusion**:
- Since both statements are correct but the reason does not provide a correct explanation for the assertion, the correct answer is that both the assertion and reason are correct, but the reason is not the correct explanation of the assertion.

### Final Answer:
- Both the assertion and reason are correct, but the reason is not the correct explanation of the assertion.