Read the featured given below and select the option for animals which correctly describes the features mentioned:
I. All are exclusively marine, triploblastic, coelomate organism with a water vascular system.
II. A small group of warm-like marine animals with the organ system levels of the organization.
III. The body is covered by a calcareous shell and is unsegmented with a distinct head, muscular foot, and visceral hump.
IV. Triploblastic, pesudocelomate animals in
which alimentary canal is complete with a well developed muscular pharynx.

Options

A. I-Asterias, II-Balanoglossus, III-Ascaris, IV-Ancylostoma
B. I-Ascaris, II-Ophiura, III-Pila, IV-Sepia
C. I-Ascaris, II-Saccoglossus, III-Sepia, IV-Ophiura
D. I-Asterias, II-Balanoglossus, III-Pila, IV-Ascaris

Answer

To solve the question, we need to analyze each of the features mentioned and identify the corresponding animal groups based on those features.

### Step-by-Step Solution:

1. **Feature I: All are exclusively marine, triploblastic, coelomate organisms with a water vascular system.**
- **Analysis:** This description fits the phylum Echinodermata, which includes marine organisms like starfish (Asterias). They are triploblastic (having three germ layers) and coelomate (having a true body cavity) and possess a unique water vascular system.
- **Conclusion:** The animal that fits this description is **Asterias**.

2. **Feature II: A small group of worm-like marine animals with the organ system level of organization.**
- **Analysis:** This description refers to the phylum Hemichordata, which includes organisms like Balanoglossus. They are characterized by a worm-like body and have an organ system level of organization.
- **Conclusion:** The animal that fits this description is **Balanoglossus**.

3. **Feature III: The body is covered by a calcareous shell and is unsegmented with a distinct head, muscular foot, and visceral hump.**
- **Analysis:** This description pertains to the phylum Mollusca. Mollusks, such as snails (Pila), have a calcareous shell, are unsegmented, and possess a distinct head, muscular foot, and visceral hump.
- **Conclusion:** The animal that fits this description is **Pila**.

4. **Feature IV: Triploblastic, pseudocoelomate animals in which the alimentary canal is complete with a well-developed muscular pharynx.**
- **Analysis:** This description matches the phylum Nematoda, which includes organisms like Ascaris. They are triploblastic, pseudocoelomate (having a body cavity that is not completely lined by mesoderm), and have a complete digestive system with a muscular pharynx.
- **Conclusion:** The animal that fits this description is **Ascaris**.

### Final Answer:
Based on the analysis above, the animals corresponding to the features mentioned are:
- I: Asterias (Echinodermata)
- II: Balanoglossus (Hemichordata)
- III: Pila (Mollusca)
- IV: Ascaris (Nematoda)