How many of the following organisms belong to the second-largest phylum?
Apple snail, Pearl, oyster, Anopheles, Culex, Aedes, Starfish, Sea urchin, Cuttlefish, Sea cucumber, Squid, Devil fish

Options

A. 9
B. 8
C. 10
D. 5

Answer

To determine how many of the listed organisms belong to the second-largest phylum, we need to identify the organisms that fall under the phylum Mollusca.

### Step-by-Step Solution:

1. **Identify the Second Largest Phylum**:
- The second-largest phylum in the animal kingdom is the phylum Mollusca.

2. **List the Given Organisms**:
- Apple snail
- Pearl oyster
- Anopheles
- Culex
- Aedes
- Starfish
- Sea urchin
- Cuttlefish
- Sea cucumber
- Squid
- Devil fish

3. **Classify Each Organism**:
- **Apple snail**: Belongs to phylum Mollusca.
- **Pearl oyster**: Belongs to phylum Mollusca.
- **Anopheles**: Belongs to phylum Arthropoda.
- **Culex**: Belongs to phylum Arthropoda.
- **Aedes**: Belongs to phylum Arthropoda.
- **Starfish**: Belongs to phylum Echinodermata.
- **Sea urchin**: Belongs to phylum Echinodermata.
- **Cuttlefish**: Belongs to phylum Mollusca.
- **Sea cucumber**: Belongs to phylum Echinodermata.
- **Squid**: Belongs to phylum Mollusca.
- **Devil fish (Octopus)**: Belongs to phylum Mollusca.

4. **Count the Organisms in Mollusca**:
- From the list, the organisms that belong to phylum Mollusca are:
- Apple snail
- Pearl oyster
- Cuttlefish
- Squid
- Devil fish (Octopus)
- Total: 5 organisms.

5. **Conclusion**:
- Therefore, the number of organisms from the list that belong to the second-largest phylum (Mollusca) is **5**.

### Final Answer:
**5 organisms belong to the second-largest phylum, Mollusca.**

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