Assertion (A) : Agarose gel electrophoresis is used to check the progression of a restriction enzyme digestion. Reason (R) : Restriction enzyme digestions are performed by incubating purified DNA molecules with restriction enzyme.

Options

A. Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
B. Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
C. Assertion (A) is true but reason (R) is false.
D. Assertion (A) is false but reason (R) is true.

Explanation

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "Agarose gel electrophoresis is used to check the progression of a restriction enzyme digestion." This means that after performing a restriction enzyme digestion on DNA, agarose gel electrophoresis can be utilized to visualize the results and confirm whether the digestion has occurred as expected.

2. **Understanding the Reason (R)**:
- The reason states that "Restriction enzyme digestions are performed by incubating purified DNA molecules with restriction enzyme." This explains the method by which restriction enzymes act on DNA to cut it into smaller fragments.

3. **Analyzing the Truth of Assertion (A)**:
- Agarose gel electrophoresis is indeed a common technique used in molecular biology to separate DNA fragments based on size. It allows researchers to see if the DNA has been successfully cut by the restriction enzymes, thus confirming the progression of the digestion process. Therefore, Assertion (A) is true.

4. **Analyzing the Truth of Reason (R)**:
- The reason provided is also true as restriction enzyme digestion involves incubating purified DNA with restriction enzymes to achieve the cutting of DNA into fragments. Thus, Reason (R) is true.

5. **Evaluating the Relationship between Assertion and Reason**:
- Although both the assertion and reason are true, the reason does not directly explain the assertion. The assertion is about the use of agarose gel electrophoresis to check the progression of digestion, while the reason describes the process of how the digestion occurs. Therefore, the reason is not the correct explanation for the assertion.

6. **Conclusion**:
- Both the assertion and the reason are true, but the reason does not correctly explain the assertion. Hence, the correct answer is that both the assertion and reason are true, but the reason is not the correct explanation of the assertion.