All animals are marine in

Options

A. Ctenophora
B. Echinodermata
C. Protochordata
D. All of the above

Answer

To solve the question "All animals are marine in," we need to analyze the options provided: Tenophora, Echinodermata, Protocordata, and "all of the above."

### Step-by-Step Solution:

1. **Understand Marine Animals**:
- Marine animals are those that live in saltwater environments, such as oceans and seas.

2. **Examine Tenophora**:
- Tenophora, commonly known as comb jellies, are predominantly marine animals. They are known for their gelatinous bodies and are found in oceanic waters.

3. **Examine Echinodermata**:
- Echinodermata includes starfish, sea urchins, and sea cucumbers, which are also exclusively marine animals. They are characterized by their radial symmetry and a water vascular system.

4. **Examine Protocordata**:
- Protocordata includes animals like lancelets and tunicates. While many of these organisms are marine, they represent a transitional group between invertebrates and vertebrates.

5. **Analyze the Options**:
- Since Tenophora and Echinodermata are entirely marine, and Protocordata includes primarily marine species, we can conclude that all the options provided contain marine animals.

6. **Conclusion**:
- Therefore, the correct answer to the question "All animals are marine in" is **Option 4: All of the above**.

### Final Answer:
**Option 4: All of the above**

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