Which is correctly paired ?

Options

A. Heart-Involuntary, unstriated muscle
B. Iris-Involuntary, smooth muscle
C. Biceps-Smooth muscle
D. Abdominal Wall-smooth muscle.

Answer

To solve the question "Which is correctly paired?" we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Heart**:
- The heart is made up of cardiac muscle, which is involuntary.
- It is incorrect to say that the heart has unstriated muscle because unstriated muscles refer to smooth muscles, which are different from cardiac muscles.
- **Conclusion**: This pairing is incorrect.

2. **Iris**:
- The iris contains smooth muscle, which is involuntary.
- These muscles help in the accommodation of the pupil, allowing it to contract or dilate in response to light changes.
- **Conclusion**: This pairing is correct.

3. **Biceps**:
- The biceps are skeletal muscles, which are striated and voluntary.
- They are not smooth muscles.
- **Conclusion**: This pairing is incorrect.

4. **Abdominal Muscles**:
- The abdominal muscles are indeed smooth muscles and are involuntary, meaning they function without conscious control.
- **Conclusion**: This pairing is correct.

### Final Answer:
The correctly paired options are:
- **B (Iris - Involuntary Smooth Muscle)**
- **D (Abdominal Muscles - Smooth Muscles)**