[A]: Spore mother cells within the anther pollen sacs form four haploid pollen grains.
[R]: Spore mother cells divide meiotically to form four haploid pollen grains.

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

To solve the question regarding the assertion and reason provided, we will analyze each statement step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states: "Spore mother cells within the anther pollen sacs form four haploid pollen grains."
- This refers to the process of microsporogenesis, where diploid microspore mother cells (also known as microsporocytes) undergo meiosis to produce haploid microspores.

2. **Understanding the Reason (R)**:
- The reason states: "Spore mother cells divide meiotically to form four haploid pollen grains."
- This indicates that the spore mother cells undergo meiotic division, which is indeed the correct process leading to the formation of haploid pollen grains.

3. **Evaluating the Truth of Each Statement**:
- **Assertion (A)**: True. The assertion correctly describes the outcome of microsporogenesis, where spore mother cells in the anther produce four haploid pollen grains.
- **Reason (R)**: True. The reason accurately describes the process (meiotic division) that leads to the formation of these haploid pollen grains.

4. **Determining the Relationship Between A and R**:
- While both statements are true, we need to assess whether the reason correctly explains the assertion.
- The reason explains the process (meiotic division) but does not elaborate on the specific context of pollen grain formation from the spore mother cells.

5. **Conclusion**:
- Both the assertion and reason are true, but the reason is not a correct explanation of the assertion. Therefore, the correct answer is that both A and R are true, but R is not the correct explanation of A.

### Final Answer:
Both A and R are true, but R is not the correct explanation of A.

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