**Core Concept**
The question is testing the understanding of the molecular structure and function of skeletal muscles, specifically the interaction between myosin and actin filaments. This concept is crucial for understanding muscle contraction and relaxation mechanisms.

**Why the Correct Answer is Right**
Myosin heads bind to actin filaments through a process called cross-bridge cycling, which is essential for muscle contraction. The myosin heads contain a binding site for actin, which is covered by a regulatory protein called tropomyosin. When the muscle is stimulated to contract, tropomyosin is shifted away from the myosin binding site, allowing myosin to bind to actin and initiate contraction. This process is mediated by the troponin-tropomyosin complex, which regulates the interaction between myosin and actin.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a protein or structure that covers the myosin binding site on actin.
**Option B:** This option is incorrect because it does not accurately describe the regulatory protein that covers the myosin binding site on actin.
**Option C:** This option is incorrect because it is a component of the muscle sarcomere, but it is not the protein that covers the myosin binding site on actin.

**Clinical Pearl / High-Yield Fact**
It is essential to remember that the interaction between myosin and actin is regulated by the troponin-tropomyosin complex, which is sensitive to calcium ions. This regulatory mechanism is crucial for muscle contraction and relaxation.

**Correct Answer:** C. Tropomyosin