Assertion : It is not a safe option to carry umbrella at the time of thunder storm.
Reason : Taking umbrella will increase the risk of fall of lightning on the person.

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 assertion is false but reason is true.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**: The assertion states that it is not safe to carry an umbrella during a thunderstorm. This is a valid statement because thunderstorms are associated with lightning, which can be extremely dangerous.

**Hint**: Think about the conditions during a thunderstorm and the potential dangers involved.

2. **Analyzing the Reason**: The reason provided is that carrying an umbrella increases the risk of being struck by lightning. This is true because umbrellas typically have metal rods, which are good conductors of electricity.

**Hint**: Consider the properties of metals and how they interact with electrical charges, especially in the context of lightning.

3. **Connection Between Assertion and Reason**: The reason explains why the assertion is true. The presence of metal rods in an umbrella can attract lightning, making it more dangerous to carry one during a thunderstorm.

**Hint**: Reflect on how the properties of materials (like metal) can influence safety in electrical phenomena.

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.

**Hint**: Look for options that indicate both statements are true and that one explains the other.

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