Contractile protein of skeletal muscle involving ATPase activity is :-

Options

A. Troponin
B. Tropomyosin
C. Myosin
D. `alpha` -actinin

Answer

To solve the question regarding the contractile protein of skeletal muscle that involves ATPase activity, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the contractile protein in skeletal muscle that has ATPase activity. ATPase activity refers to the ability of a protein to hydrolyze ATP, which is crucial for muscle contraction.

2. **Analyze the Options**: The options given are:
- Troponin
- Tropomyosin
- Myosin
- Alpha-actinin

3. **Identify the Role of Each Protein**:
- **Troponin**: This is a regulatory protein that binds to calcium ions and helps in the regulation of muscle contraction but does not have ATPase activity.
- **Tropomyosin**: This protein wraps around actin filaments and blocks the binding sites for myosin, thus it is also not involved in ATPase activity.
- **Myosin**: This is a contractile protein that has ATPase activity. It interacts with actin to facilitate muscle contraction and is known for its role in converting chemical energy from ATP into mechanical energy.
- **Alpha-actinin**: This is an actin-binding protein that helps in organizing actin filaments but does not have ATPase activity.

4. **Conclude with the Correct Answer**: Based on the analysis, the only protein listed that is a contractile protein of skeletal muscle and involves ATPase activity is **Myosin**.

### Final Answer:
The correct option is **Myosin**.

---