Which one of the following statements about centain given animals is correct

Options

A. Round worms ( Aschelminthes ) are pseudocoelomates
B. Molluscs are acoelomates
C. Insects are pseudocoelomates
D. Flat worms (Platyhelminthes ) are coelomates

Answer

To solve the question regarding which statement about certain animals is correct, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Terms**:
- First, we need to understand the terms used in the statements:
- **Pseudocoelomates**: Animals that have a body cavity (coelom) that is not entirely lined by mesoderm.
- **Coelomates**: Animals that have a true coelom, which is a body cavity completely lined by mesoderm.
- **Acoelomates**: Animals that do not have a body cavity.

2. **Evaluate the First Statement**:
- The first statement claims that "roundworms are pseudocoelomates."
- This is true because roundworms (like those in the phylum Nematoda) have a pseudocoelom, which is derived from the blastocoel and not from mesoderm.

3. **Evaluate the Second Statement**:
- The second statement claims that "mollusks are coelomates."
- This is also true. Mollusks (phylum Mollusca) have a true coelom.

4. **Evaluate the Third Statement**:
- The third statement claims that "insects are pseudocoelomates."
- This is false. Insects (phylum Arthropoda) are coelomates.

5. **Evaluate the Fourth Statement**:
- The fourth statement claims that "flatworms are coelomates."
- This is false. Flatworms (phylum Platyhelminthes) are acoelomates, meaning they do not have a body cavity.

6. **Conclusion**:
- Based on the evaluations, the correct statement is that roundworms are pseudocoelomates.

### Final Answer:
- The correct statement is: **"Roundworms are pseudocoelomates."**