An ascidian is

Options

A. Balanoglossus
B. Herdmania
C. Branchiostoma
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
- The question asks to identify what an ascidian is and to which group it belongs.

2. **Identifying the Options:**
- The options provided are:
1. Balenoglossus
2. Hermania
3. Brachiostoma
4. None of the above

3. **Analyzing Each Option:**
- **Balenoglossus:** This organism belongs to the phylum Hemichordata. Therefore, it is not related to ascidians.
- **Hermania:** This organism is classified under the phylum Urochordata, which is the same phylum that ascidians belong to.
- **Brachiostoma:** This organism belongs to the phylum Cephalochordata, which is also not related to ascidians.
- **None of the above:** This option implies that none of the previous options are correct.

4. **Conclusion:**
- Since ascidians are classified under the phylum Urochordata and Hermania is also part of this phylum, the correct answer is option 2: Hermania.

5. **Final Answer:**
- An ascidian is Hermania.

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