Assertion `:` The pause between the end of the second sound and the beginning of the first sound coincides with ventricular diastole.
Reason `:` The second sound (dupp) is created by the closure of the semilunar valve.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion .
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are false.

Answer

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the pause between the end of the second heart sound (dub) and the beginning of the first heart sound (lub) coincides with ventricular diastole.
- Ventricular diastole is the phase of the cardiac cycle when the ventricles relax and fill with blood.

2. **Understanding the Reason**:
- The reason states that the second sound (dub) is created by the closure of the semilunar valves.
- The semilunar valves include the aortic valve and the pulmonary valve, which close at the end of ventricular systole (when the heart contracts).

3. **Evaluating the Assertion**:
- The assertion is correct because during the pause between the heart sounds, the heart is in the diastolic phase, allowing the ventricles to fill with blood.

4. **Evaluating the Reason**:
- The reason is also correct because the second heart sound (dub) indeed results from the closure of the semilunar valves.

5. **Determining the Relationship**:
- While both statements are true, the reason does not directly explain the assertion. The closure of the semilunar valves (which creates the second sound) does not cause the pause that coincides with ventricular diastole.

6. **Conclusion**:
- Therefore, the correct option is that both the assertion and reason are true, but the reason is not a correct explanation of the assertion.

### Final Answer:
The assertion is true, the reason is true, but the reason is not a correct explanation of the assertion.

---