Assertion : `Ca^(2+)` plays important role in the musclc contraction.
Reason : `Ca^(2+)` Combines with troponin chain, displacing tropomyosin allowing the myosin head part to combine with actin to from actomyosin complex .
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
(b (b) If both Assertion and Reason are true, but the Reason is not the correct explanation of the Assertion.
(c) If Assertion is true, but Reason is false .
(d) If both Assertion and Reason are false.

Options

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

Answer

To solve the question, we need to evaluate the assertion and the reason provided:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that `Ca^(2+)` plays an important role in muscle contraction. This is true because calcium ions are crucial for initiating the contraction process in muscle fibers.

2. **Understanding the Reason**:
- The reason states that `Ca^(2+)` combines with the troponin chain, displacing tropomyosin, which allows the myosin head to combine with actin to form the actomyosin complex. This is also true, as calcium ions bind to troponin, leading to a conformational change that moves tropomyosin away from the binding sites on actin, allowing myosin to attach.

3. **Evaluating the Relationship**:
- Since both the assertion and the reason are true, we need to determine if the reason correctly explains the assertion. The reason describes the mechanism by which calcium ions facilitate muscle contraction, thus providing a correct explanation for the assertion.

4. **Conclusion**:
- Since both the assertion and reason are true and the reason correctly explains the assertion, the correct answer is (a): If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.

### Final Answer:
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.