Muscles of heart are

Options

A. Striated and voluntary
B. Nonstriated and voluntary
C. Striated unbranched and involuntary
D. Striated , branched and involuntary .

Answer

### Step-by-Step Solution:

1. **Understanding Heart Muscles**: The muscles of the heart are known as cardiac muscles. It is essential to know their characteristics to answer the question correctly.

2. **Identifying Characteristics**:
- Cardiac muscles are **striated**, meaning they have a banded appearance due to the arrangement of muscle fibers.
- They are **branched**, which is a unique feature that distinguishes them from other muscle types.
- Cardiac muscles are **involuntary**, meaning they are not under conscious control and function automatically.

3. **Evaluating Options**:
- **Option 1**: "Striated voluntary" - This is incorrect because, while cardiac muscles are striated, they are not voluntary.
- **Option 2**: "Non-striated and voluntary" - This is incorrect as cardiac muscles are striated and involuntary.
- **Option 3**: "Striated unbranched involuntary" - This is incorrect because although they are striated and involuntary, they are not unbranched; they are branched.
- **Option 4**: "Striated branched and involuntary" - This is correct as it accurately describes cardiac muscles.

4. **Conclusion**: The correct answer is **Option 4**: "Striated branched and involuntary."