Assertion (A): Surgical methods are most effective methods of contraception.
Reason ( R): Surgical method blocks gametes transport and hence prevent fertilisation.

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is NOT the correct explanation of A.
C. A is true but R is false.
D. A is false and R is true.

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that "Surgical methods are the most effective methods of contraception."
- Surgical methods of contraception include procedures like vasectomy (for males) and tubectomy (for females). These methods are designed to permanently prevent pregnancy by blocking the transport of gametes.

### Step 2: Understand the Reason
The reason states that "Surgical methods block gamete transport and hence prevent fertilization."
- Surgical methods indeed block the transport of sperm in males and eggs in females, which prevents fertilization from occurring. For instance, in vasectomy, the vas deferens is cut, preventing sperm from being released. In tubectomy, the fallopian tubes are cut, preventing eggs from reaching the uterus.

### Step 3: Evaluate the Relationship
Now we need to determine if the reason correctly explains the assertion.
- The assertion is true because surgical methods are indeed very effective in preventing pregnancy. The reason is also true because these methods block the transport of gametes, which is the mechanism through which they prevent fertilization.

### Step 4: Conclusion
Since both the assertion and the reason are true, and the reason correctly explains the assertion, the correct answer is:
**Option A: Both assertion and reason are true, and the reason is the correct explanation of the assertion.**

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