Which is unralated ?

Options

A. Sea Cucumber
B. Sea Star
C. Sea Urchin
D. Sea Squid

Answer

To determine which option is unrelated among the given choices, we need to analyze each option based on their classification in the animal kingdom.

### Step-by-Step Solution:

1. **Identify the Options**:
- A) Sea Cucumber
- B) Sea Star
- C) Sea Urchin
- D) Squid

2. **Classify Each Option**:
- **Sea Cucumber**: This organism belongs to the class Holothuroidea within the phylum Echinodermata. They are marine animals characterized by their leathery skin and elongated body.
- **Sea Star**: This organism belongs to the class Asteroidea, also within the phylum Echinodermata. They are star-shaped echinoderms found on the seabed in oceans worldwide.
- **Sea Urchin**: This organism belongs to the class Echinoidea, again within the phylum Echinodermata. They are small, spiny, and globular animals.
- **Squid**: This organism belongs to the class Cephalopoda within the phylum Mollusca. Squids are marine animals known for their intelligence and ability to swim quickly.

3. **Determine the Unrelated Organism**:
- The first three options (Sea Cucumber, Sea Star, and Sea Urchin) are all classified under the phylum Echinodermata, meaning they share similar characteristics and evolutionary lineage.
- The Squid, on the other hand, is classified under the phylum Mollusca, which is entirely different from Echinodermata.

4. **Conclusion**:
- The unrelated organism among the options is **Squid** (Option D), as it does not belong to the Echinodermata phylum.

### Final Answer:
**D) Squid** is the unrelated option.

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