The water vascular system in phylum echinodermata helps in

Options

A. Locomotion, capture and transport of food
B. Excretion
C. Respiration
D. All of these

Explanation

### Step-by-Step Solution:

1. **Understanding Echinodermata**:
- Echinodermata is a phylum that consists of marine animals such as starfish, sea urchins, and sea cucumbers. They are characterized by their unique features, including a water vascular system.

2. **Water Vascular System**:
- The water vascular system is a hydraulic system that plays a crucial role in the physiology of echinoderms. It consists of a network of fluid-filled canals and tube feet.

3. **Functions of the Water Vascular System**:
- **Locomotion**: The water vascular system helps in movement. The contraction of muscles within the system forces water into the tube feet, allowing echinoderms to extend and retract their feet for movement.
- **Capture and Transport of Food**: The tube feet, powered by the water vascular system, can also help in capturing food and moving it towards the mouth.
- **Excretion**: The water vascular system aids in the removal of waste products from the body.
- **Respiration**: It also plays a role in gas exchange, allowing for respiration through the tube feet and other structures.

4. **Conclusion**:
- Given that the water vascular system in echinoderms assists in locomotion, food capture and transport, excretion, and respiration, we can conclude that the correct answer to the question is "all of these."

5. **Final Answer**:
- Therefore, the answer is **Option D: All of these**.