Assertion : Natural methods are based on menstrual cycle and the life of sperms
Reason : Natural methods often fail to contracept.

Options

A. If both Assertion and Reason are true but the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion and Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
C. If Assertion is true but Reason is false, then mark (3).
D. If both Assertion and Reason are false, then mark (4).

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 "Natural methods are based on menstrual cycle and the life of sperms."
- This is true because natural contraceptive methods, such as periodic abstinence, rely on understanding the menstrual cycle (when ovulation occurs) and the lifespan of sperm (which can survive for several days in the female reproductive tract).

2. **Understanding the Reason**:
- The reason states that "Natural methods often fail to contracept."
- This is also true. Natural methods can have a higher failure rate compared to other contraceptive methods because they rely on precise timing and self-control, which can be difficult to achieve consistently.

3. **Evaluating the Relationship**:
- Now we need to determine whether the reason correctly explains the assertion.
- While both statements are true, the reason does not directly explain why the assertion is true. The assertion is about the basis of natural methods, while the reason discusses their effectiveness.

4. **Conclusion**:
- Since both the assertion and reason are true, but the reason does not provide a correct explanation for the assertion, the correct answer is option 2: "If both assertion and reason are true, but reason is not the correct explanation of the assertion."

### Final Answer:
The correct option is 2: Both assertion and reason are true, but reason is not the correct explanation of the assertion.

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