Acorn worms are included in which of the following phylum?

Options

A. Echinodermata
B. Hemichordata
C. Mollusca and Echinodermata
D. Annelida

Explanation

**Step-by-Step Solution:**

1. **Identify the Organism**: The question asks about "Acorn worms." It is important to first understand what acorn worms are.

2. **Common Name and Scientific Classification**: Acorn worms are also known scientifically as "Enteropneusta." This is a key term that helps in identifying the correct phylum.

3. **Determine the Phylum**: Acorn worms belong to the phylum Hemichordata. This phylum is known for its invertebrate organisms.

4. **Class and Order**: Within the phylum Hemichordata, acorn worms are classified under the class Enteropneusta, which is the same name as their scientific classification.

5. **Comparison with Other Phyla**: The question provides several options: Echinodermata, Hemichordata, Mollusca, and others. It is essential to differentiate Hemichordata from Echinodermata (which includes starfish) and Mollusca (which includes octopus and squids).

6. **Feeding and Habitat**: Acorn worms are known to be deposit feeders and live in sediments on the seabed, which further supports their classification in Hemichordata.

7. **Conclusion**: Based on the classification and characteristics discussed, the correct answer to the question is that acorn worms are included in the phylum Hemichordata.

**Final Answer**: Acorn worms are included in the phylum Hemichordata.

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