Which one of the following statements about certain given animals is corret?

Options

A. Roundworms are pseudocoelomates.
B. Mollucus are acoelomates.
C. Annelids are pseudocoelomates.
D. Flatworms are coelomates.

Explanation

To determine which statement about the given animals is correct, we need to analyze the options based on the classification of animals according to the presence of a coelom. Here’s a step-by-step solution:

### Step 1: Understand the Types of Coelom
Animals are classified based on the presence and type of coelom into three main categories:
1. **Coelomates**: Animals that have a true coelom, which is a body cavity lined by mesoderm.
2. **Pseudocoelomates**: Animals that have a pseudocoelom, which is a body cavity not completely lined by mesoderm.
3. **Acoelomates**: Animals that lack a coelom entirely.

### Step 2: Analyze the Options
Now, let's evaluate each option provided in the question:

1. **Roundworms are pseudocoelomates**: This statement is correct. Roundworms (Nematoda) possess a pseudocoelom, which is a body cavity that is not fully lined by mesoderm.

2. **Molluscs are acoelomates**: This statement is incorrect. Molluscs (Mollusca) are coelomates, meaning they have a true coelom.

3. **Annelids are pseudocoelomates**: This statement is incorrect. Annelids (Annelida) are coelomates, as they possess a true coelom.

4. **Worms are coelomates**: This statement is too vague and incorrect in a general sense, as it does not specify which type of worms. While some worms (like annelids) are coelomates, others (like flatworms) are acoelomates.

### Step 3: Conclusion
Based on the analysis, the only correct statement is:
- **Roundworms are pseudocoelomates**.

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

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