Assertion (A): In humans, males play an important role in determining the sex of the child.
Reason (R): Males have two X chromosomes.

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

**Step-by-Step Solution:**

1. **Understanding the Assertion (A)**: The assertion states that in humans, males play an important role in determining the sex of the child. This is true because the male gamete (sperm) carries either an X or a Y chromosome, which directly influences the sex of the offspring.

2. **Understanding the Reason (R)**: The reason states that males have two X chromosomes. This is incorrect. In humans, males have one X and one Y chromosome (XY), while females have two X chromosomes (XX).

3. **Analyzing the Relationship**: Since the assertion is correct (males do determine the sex of the child) but the reason is incorrect (males do not have two X chromosomes), we need to evaluate the options provided.

4. **Identifying the Correct Option**: Based on the analysis, the correct option is that the assertion is correct but the reason is wrong. This corresponds to option three.

5. **Conclusion**: Therefore, the final answer is that the assertion is true, and the reason is false.

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