The internal body covering the mantle in mollusc is for

Options

A. Respiration
B. Protection of body organs
C. Shell formation
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding the Mantle**: The mantle is an important internal body covering in molluscs. It is a significant structure that plays various roles in the physiology of these organisms.

2. **Composition of the Mantle**: The mantle is composed of proteins, chitin, and calcium carbonate (CaCO3). Each of these components contributes to different functions.

3. **Function of Proteins**: The proteins found in the mantle are involved in respiration. They facilitate gas exchange, allowing the mollusc to breathe.

4. **Role of Chitin**: Chitin is a polysaccharide that provides structural support and hardness to the mantle. This hardness is crucial for the protection of the mollusc's body organs.

5. **Calcium Carbonate's Contribution**: Calcium carbonate is essential for shell formation. It helps in creating the hard outer shell that protects the mollusc from predators and environmental factors.

6. **Summary of Functions**:
- **Respiration**: The proteins in the mantle assist in the respiratory process.
- **Protection**: Chitin provides a protective layer for the internal organs.
- **Shell Formation**: Calcium carbonate contributes to the formation of the mollusc's shell.

7. **Conclusion**: Therefore, the internal body covering of the mantle in molluscs serves multiple functions: respiration, protection of body organs, and shell formation. The correct answer is that the mantle is responsible for all of the above functions.