Which of the following statements are correct regarding muscle proteins ?
(i) Actin is a thin filament and is mde up to two F-actin
(ii) The complex protein, tropomyosin is distributed at regular intervals on the troponin
(iii) Myosin is a thick filament which is also a polymerised protein.
(iv) The globular head of meromyosin consists of light meromyosin (LMM).

Options

A. (i), (ii) and (iii)
B. (i), (ii) and (iv)
C. (i) and (iii)
D. (ii) and (iv)

Explanation

To determine which statements regarding muscle proteins are correct, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement (i): Actin is a thin filament and is made up of two F-actins.**
- **Analysis**: Actin is indeed a thin filament in muscle fibers. It is composed of two strands of F-actin (filamentous actin) that are helically wound around each other. Therefore, this statement is **correct**.

2. **Statement (ii): The complex protein, tropomyosin is distributed at regular intervals on the troponin.**
- **Analysis**: In muscle fibers, tropomyosin runs along the length of the actin filaments, and troponin is attached at regular intervals along the tropomyosin. The statement incorrectly states that tropomyosin is distributed on troponin, which is the opposite of the correct arrangement. Thus, this statement is **incorrect**.

3. **Statement (iii): Myosin is a thick filament which is also a polymerized protein.**
- **Analysis**: Myosin is indeed a thick filament and is a polymerized protein. It is made up of monomers called meromyosin. Therefore, this statement is **correct**.

4. **Statement (iv): The globular head of meromyosin consists of light meromyosin (LMM).**
- **Analysis**: The globular head of myosin (which is part of meromyosin) is actually made up of heavy meromyosin (HMM), not light meromyosin (LMM). Light meromyosin constitutes the tail of the myosin molecule. Therefore, this statement is **incorrect**.

### Conclusion:
Based on the analysis:
- Correct statements: (i) and (iii)
- Incorrect statements: (ii) and (iv)

Thus, the correct answer is that statements **(i)** and **(iii)** are correct.