Haemocyanin is found in

Options

A. Neries
B. Leech
C. Earthworm
D. Prawn

Explanation

**Step-by-Step Solution:**

1. **Understanding Haemocyanin**: Haemocyanin is a type of respiratory pigment that contains copper and is typically blue when oxygenated. It serves a similar function to hemoglobin in vertebrates, which contains iron.

2. **Identifying Organisms**: Haemocyanin is found in certain invertebrates, particularly in the phyla of arthropods and mollusks. It is commonly associated with organisms like crustaceans and some gastropods.

3. **Analyzing the Options**: The question provides four options: Nereis, Leech, Arthvom, and Prone. We need to determine which of these organisms contains haemocyanin.

4. **Evaluating Each Option**:
- **Nereis**: This is a genus of polychaete worms, which typically do not have haemocyanin.
- **Leech**: Leeches are annelids and primarily use hemoglobin for oxygen transport, not haemocyanin.
- **Arthvom**: This option seems to be a typographical error or misrepresentation; however, if it refers to arthropods, then it could potentially contain haemocyanin.
- **Prone**: This is likely referring to "prone" as a misrepresentation of "crustaceans" or "prone" organisms, which are known to have haemocyanin.

5. **Conclusion**: Based on the information, haemocyanin is primarily found in crustaceans and some gastropods. Among the options provided, "Prone" is the best fit as it likely refers to organisms that contain haemocyanin.

**Final Answer**: Haemocyanin is found in **Prone** (Option D).

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