True fish is

Options

A. Whale/Cuttle Fish
B. Silver Fish
C. Cray Fish /Jelly Fish
D. Flying Fish/Cat Fish

Answer

### Step-by-Step Solution:

1. **Understanding True Fish**:
- True fish are defined as those that belong to the phylum Chordata, specifically under the subphylum Vertebrata, and are classified in the class Pisces.

2. **Evaluating the Options**:
- We need to analyze each option provided to determine which ones are true fish.

3. **Option 1: Whale and Cuttlefish**:
- **Whale**: Whales belong to the class Mammalia, making them mammals, not fish.
- **Cuttlefish**: Cuttlefish are mollusks, not fish.
- **Conclusion**: This option is incorrect.

4. **Option 2: Silverfish**:
- **Silverfish**: Silverfish are arthropods and classified as insects, not fish.
- **Conclusion**: This option is incorrect.

5. **Option 3: Crayfish and Jellyfish**:
- **Crayfish**: Crayfish are freshwater crustaceans, resembling small lobsters, and are not true fish.
- **Jellyfish**: Jellyfish belong to the phylum Cnidaria, which also makes them not fish.
- **Conclusion**: This option is incorrect.

6. **Option 4: Flying Fish and Catfish**:
- **Flying Fish**: Flying fish belong to the family Exocetidae and are classified under class Pisces, making them true fish.
- **Catfish**: Catfish belong to the family Ictaluridae and are also classified under class Pisces, making them true fish.
- **Conclusion**: This option is correct.

7. **Final Answer**: The true fish are the flying fish and catfish.