Assertion : Surgical method blocks gamete transport and thereby prevents conception.
Reason : Surgical method used in males for this purpose is called vasectomy.

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 evaluate the assertion and the reason provided, and determine their truthfulness and relationship.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Surgical method blocks gamete transport and thereby prevents conception."
- This is true because surgical methods, such as sterilization techniques, are designed to block the transport of gametes (sperm in males and eggs in females), which prevents fertilization and thus conception.

2. **Understanding the Reason**:
- The reason states that "Surgical method used in males for this purpose is called vasectomy."
- This is also true. Vasectomy is a surgical procedure that involves cutting and tying the vas deferens in males, which prevents sperm from being included in the ejaculate, thereby preventing conception.

3. **Evaluating the Relationship**:
- While both the assertion and the reason are true, we need to assess if the reason is the correct explanation of the assertion.
- The assertion discusses the general concept of surgical methods blocking gamete transport, while the reason specifically identifies vasectomy as one such method in males. However, it does not explain why surgical methods block gamete transport in general.

4. **Conclusion**:
- Since both the assertion and reason are true, but the reason does not correctly explain the assertion, we conclude that the correct answer is option 2: "Both assertion and reason are true, but the reason is not the correct explanation of the assertion."

### Final Answer:
The correct answer is option 2.

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