Assertion: Crystal protein does not kill the Bacillus & kill only insect
Reason :In Bacillus it exist as inactive proteins but in insect it is converted into an active form due to acidic pH of the gut

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion
B. It both Assertion & Reason are True but Reason is not a correct explanation of the Assetion
C. If Assertion is True but the Reason is False
D. If both Assertion & Reason are false

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that crystal protein does not kill Bacillus and only kills insects. This is true because the crystal protein produced by Bacillus thuringiensis (Bt) is in an inactive form when contained within the bacterium. It does not harm the bacterium itself.

**Hint**: Remember that the crystal protein is a protective mechanism for the bacterium and does not affect its survival.

2. **Understanding the Reason**: The reason provided states that in Bacillus, the crystal protein exists as inactive proteins, but in insects, it is converted into an active form due to the acidic pH of the gut. This part is misleading. While it is true that the crystal protein is inactive in Bacillus, it is not activated by acidic pH in insects; rather, it is activated by the alkaline pH of the insect gut.

**Hint**: Focus on the pH levels in the insect gut and how they affect the activation of the crystal protein.

3. **Evaluating the Relationship**: The assertion is true, but the reason is false. The reason does not correctly explain the assertion because the activation of the crystal protein occurs in an alkaline environment, not an acidic one.

**Hint**: Check the conditions under which the crystal protein becomes active and relate it back to the assertion.

4. **Conclusion**: Therefore, the final conclusion is that the assertion is true, while the reason is false.

**Hint**: Always differentiate between the truth of a statement and the correctness of its explanation.

### Final Answer:
- Assertion: True
- Reason: False