Assertion : Genetic engineering requires both nuclease and ligases.
Reason : Ligases produce the nick in the recombinant DNA molecule.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Assertion**: The assertion states that genetic engineering requires both nucleases and ligases. This is correct because both enzymes play crucial roles in the process of genetic engineering. Nucleases are responsible for cutting DNA, while ligases are responsible for joining DNA fragments together.

2. **Understanding the Reason**: The reason given is that ligases produce the nick in the recombinant DNA molecule. This statement is incorrect. Ligases do not create nicks; instead, they seal the nicks or breaks in the DNA strands after the DNA has been cut by nucleases.

3. **Evaluating the Options**:
- **Option A**: Both assertion and reason are true, and the reason is a correct explanation for the assertion. This is incorrect because the reason is false.
- **Option B**: Both assertion and reason are true, but the reason is not the correct explanation for the assertion. This is also incorrect because the reason is false.
- **Option C**: The assertion is true, but the reason is false. This is correct as the assertion is valid, but the reason provided is not accurate.
- **Option D**: The assertion is false, but the reason is true. This is incorrect because the assertion is true.

4. **Conclusion**: The correct answer is Option C, which states that the assertion is true but the reason is false.