Assertion: In diplontic life cycle, gametophyte is dominant.
Reason: In diplontic life cycle, there is not free living sporophyte.

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 but R is false.
D. If both A and R are false.

Explanation

To solve the assertion and reason question regarding the diplontic life cycle, we need to analyze both statements carefully.

### Step-by-Step Solution:

1. **Understand the Assertion**:
- The assertion states that "In diplontic life cycle, gametophyte is dominant."
- In a diplontic life cycle, the dominant phase is the diploid sporophyte, not the gametophyte. Therefore, this assertion is **incorrect**.

2. **Understand the Reason**:
- The reason provided states that "In diplontic life cycle, there is not free living sporophyte."
- In the diplontic life cycle, the sporophyte is indeed the dominant and free-living phase. The gametophyte is typically reduced and dependent on the sporophyte. Hence, this reason is also **incorrect**.

3. **Conclusion**:
- Since both the assertion and the reason are incorrect, the correct answer to the question is that both statements are false.

### Final Answer:
Both the assertion and reason are false.

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