A : Hybrid is an individual resulting from a cross between two genetically unlike parents.
R : Hybrid vigour is the superiority of hybrid over either of the parents.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true and the reason is not the correct explanation of the assertion, then mark (2).
C. If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statements, then mark (4)

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "Hybrid is an individual resulting from a cross between two genetically unlike parents."
- This means that a hybrid is formed when two different organisms (with different genetic backgrounds) are bred together.

2. **Understanding the Reason (R)**:
- The reason states that "Hybrid vigor is the superiority of hybrid over either of the parents."
- Hybrid vigor refers to the phenomenon where hybrids exhibit qualities or traits that are superior to those of their parent organisms.

3. **Evaluating the Assertion**:
- The assertion is correct because hybrids are indeed produced from the mating of two genetically different parents. This is a fundamental concept in genetics and breeding.

4. **Evaluating the Reason**:
- The reason is also correct as hybrids often show improved traits compared to their parents due to hybrid vigor.
- However, the reason does not explain why the hybrid is superior, which is a critical aspect of the relationship between the assertion and the reason.

5. **Conclusion**:
- Since both the assertion and the reason are true statements, but the reason does not adequately explain the assertion, the correct answer is that the assertion is true, but the reason is not the correct explanation for the assertion.

### Final Answer:
- Assertion (A) is true.
- Reason (R) is true but does not explain (A).
- Therefore, the correct option is that assertion is true, and reason is true but not the correct explanation.