[A]: Evolution is not occurring at present.
[R]: Evolution is a very lengthy process

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 analyze the assertion and reason provided in the question, we will follow these steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states, "Evolution is not occurring at present."
- This implies that there are no evolutionary changes happening currently.

2. **Evaluating the Assertion**:
- Evolution is a continuous process. It occurs through mechanisms such as mutations, natural selection, and genetic drift.
- Even in modern times, evolutionary changes can be observed in various species due to environmental pressures and genetic variations.
- Therefore, the assertion is **false**.

3. **Understanding the Reason**:
- The reason states, "Evolution is a very lengthy process."
- This suggests that evolution takes a long time to occur, which may imply that it does not happen quickly.

4. **Evaluating the Reason**:
- While many evolutionary changes do occur over long periods (e.g., speciation), there are also instances where evolution can happen relatively quickly, such as through mutations or rapid environmental changes.
- Thus, while evolution can be lengthy, it is not exclusively so. Therefore, the reason is also **false**.

5. **Conclusion**:
- Since both the assertion and the reason are false, the correct answer is that both statements are false.

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

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