Assertion: Evolution is adaptation through generations.
Reason: Only useful and continuous variations are inheritable.

Options

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

Answer

To analyze the given assertion and reason, we will break down the concepts of evolution, adaptation, variations, and their inheritable nature step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Evolution is adaptation through generations."
- This means that evolution involves changes in organisms over time that help them adapt to their environment. These adaptations can be beneficial traits that enhance survival and reproduction.

2. **Understanding the Reason**:
- The reason states that "Only useful and continuous variations are inheritable."
- This implies that for a variation to be passed down to the next generation, it must be both useful (beneficial for survival) and continuous (stable over generations).

3. **Evaluating the Assertion**:
- The assertion is true. Evolution is indeed a process that involves adaptations that occur over generations. These adaptations arise from genetic variations that can be influenced by environmental pressures.

4. **Evaluating the Reason**:
- The reason is partially true but misleading. While useful variations are more likely to be inherited because they provide a survival advantage, not all inheritable variations are continuous or necessarily useful. Some variations can be neutral or even harmful, yet they can still be passed on to future generations.

5. **Conclusion**:
- Since the assertion is true and the reason is not a correct explanation of the assertion, we conclude that the correct answer is:
- **Assertion is true, but the reason is false.**

### Final Answer:
- The correct option is: **Assertion is true but the reason is false.**