Assertion : Baculoviruses are biocontrol agents of genus nucleopolyhedrovirus.
Reason : They are effective against plant pathogens

Options

A. (a) If both assertion and reason are true and reason is the correct explanation of assertion.
B. (b) If both assertion and reason are true but reason is not the correct explanation of assertion.
C. (c) If assertion is true but reason is false.
D. (d) If both assertion and 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 "Baculoviruses are biocontrol agents of genus nucleopolyhedrovirus."
- Baculoviruses are indeed a type of virus that primarily infects insects and other arthropods. They are known to be used as biocontrol agents, particularly in agriculture, to manage pest populations.

2. **Understanding the Reason**:
- The reason states that "They are effective against plant pathogens."
- While baculoviruses are effective in controlling insect pests, they do not target plant pathogens. Instead, they are specific to insects and do not have an effect on plant diseases.

3. **Evaluating the Truth of Each Statement**:
- The assertion is true because baculoviruses are recognized as biocontrol agents, specifically of the genus nucleopolyhedrovirus, which affects insects.
- The reason is also true in the context that baculoviruses are effective against certain pathogens, but it is misleading because it implies they target plant pathogens, which they do not.

4. **Conclusion**:
- Both statements are true, but the reason does not explain the assertion. The assertion is about the role of baculoviruses in controlling insect pests, while the reason incorrectly suggests they target plant pathogens.

### Final Answer:
- The correct option is that both the assertion and reason are true, but the reason does not explain the assertion.