The circulatory system in balanoglossus is

Options

A. Absent
B. Open type
C. Closed type
D. Both (2) and (3)

Explanation

### Step-by-Step Solution:

1. **Identify the Organism**: Balanoglossus is a member of the phylum Hemichordata. It is important to recognize the classification of the organism to understand its biological systems.

2. **Understand Circulatory Systems**: There are two main types of circulatory systems in the animal kingdom:
- **Closed Circulation**: Blood is pumped by the heart into blood vessels, which transport it throughout the body. This system is found in organisms from phyla such as Chordata and Annelida.
- **Open Circulation**: Blood is pumped by the heart into large spaces within the body cavity, known as hemocoel, rather than being confined to blood vessels. This system is found in organisms from phyla such as Arthropoda, Mollusca, and Hemichordata.

3. **Determine the Type of Circulatory System in Balanoglossus**: Since Balanoglossus belongs to the phylum Hemichordata, it exhibits an open circulatory system. In this system, blood is not confined to vessels but flows freely in body cavities.

4. **Conclusion**: The circulatory system in Balanoglossus is classified as an open circulatory system.

### Final Answer:
The circulatory system in Balanoglossus is an open circulatory system.

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