In cartilaginous fishes, restiform (rope-like) bodies occur in

Options

A. Heart
B. Brain
C. Eyes
D. Intestine

Answer

To solve the question regarding where restiform (rope-like) bodies occur in cartilaginous fishes, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks about the location of restiform bodies in cartilaginous fishes. We need to identify which of the given options (heart, brain, eyes, intestine) is correct.

2. **Recall the Definition**: Restiform bodies are structures found in the central nervous system of certain vertebrates. They are associated with the medulla oblongata in the brain.

3. **Analyze the Options**:
- **Heart**: The heart is primarily involved in circulation and does not contain restiform bodies.
- **Brain**: The brain is the central organ of the nervous system and is known to contain restiform bodies, specifically in the medulla.
- **Eyes**: The eyes are sensory organs and do not have restiform bodies.
- **Intestine**: The intestine is part of the digestive system and does not contain restiform bodies.

4. **Identify the Correct Answer**: Based on the analysis, the only option that correctly corresponds to the presence of restiform bodies is the **brain**.

5. **Conclusion**: Therefore, the correct answer to the question is **brain**.