Assertion : Sometimes a crackling sound is heard while taking off sweater during winters.
Reason : The electric discharge takes place between body and sweater.

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 Text Solution:**

1. **Understanding the Assertion**: The assertion states that a crackling sound is sometimes heard when taking off a sweater during winters. This is a common experience for many people, especially in dry winter conditions.

2. **Understanding the Reason**: The reason given is that an electric discharge occurs between the body and the sweater. This is related to the phenomenon of static electricity.

3. **Static Electricity Formation**: When we wear woolen or synthetic clothes, friction occurs between the fabric and our skin. This friction can cause electrons to transfer from one material to another, leading to the buildup of static electricity.

4. **Discharge of Static Electricity**: When we remove the sweater, the accumulated static charge can discharge suddenly. This discharge can create a small spark or crackling sound, which is what we hear.

5. **Conclusion**: Both the assertion and the reason are true. The crackling sound is indeed caused by the electric discharge that occurs between the body and the sweater when the sweater is removed.

6. **Final Answer**: Therefore, the correct option is that both the assertion and the reason are true, and the reason is the correct explanation of the assertion.

---