Flatworms are mostly

Options

A. ectoparasites
B. coelomates
C. endoparasites
D. free living

Answer

To answer the question "Flatworms are mostly," we can break down the information provided in the video transcript step by step.

### Step-by-Step Solution:

1. **Understanding Flatworms**: Flatworms belong to the phylum Platyhelminthes. They exhibit bilateral symmetry and have an unsegmented body structure.

2. **Types of Flatworms**: Flatworms can be categorized based on their lifestyle. They can be free-living or parasitic.

3. **Parasitic Nature**: The transcript indicates that flatworms are mostly parasitic. They can be classified as endoparasites, meaning they live inside the host organism.

4. **Presence of Coelom**: It is also mentioned that flatworms lack a coelom (the body cavity), which is a characteristic feature of this group.

5. **Conclusion**: Given that flatworms are primarily endoparasites, we can conclude that the correct answer to the question is that flatworms are mostly endoparasites.

### Final Answer:
Flatworms are mostly **endoparasites**.

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