Radial symmetry is seen in

Options

A. Mollusca
B. Protozoa
C. Arthropoda
D. Sponges

Answer

### Step-by-Step Solution:

1. **Understanding Radial Symmetry**:
- Radial symmetry refers to the arrangement of body parts around a central axis, allowing an organism to be divided into equal halves from any plane that passes through the center.

**Hint**: Think about how a starfish can be split into equal parts from multiple angles.

2. **Identifying Organisms with Radial Symmetry**:
- Organisms that exhibit radial symmetry include members of the phylum Cnidaria (formerly known as Coelenterata), such as jellyfish and sea anemones.

**Hint**: Remember that jellyfish have a bell shape which allows them to be divided equally from the center.

3. **Examples of Radial Symmetry**:
- In the adult stage, organisms like sea anemones and jellyfish show radial symmetry. In contrast, their larval stages may exhibit bilateral symmetry.

**Hint**: Consider how the adult form of a jellyfish looks compared to its larval form.

4. **Porifera and Radial Symmetry**:
- While most sponges (phylum Porifera) do not exhibit any symmetry, certain tubular sponges like Cycon and Leucosolenia can demonstrate radial symmetry.

**Hint**: Think of how some sponges have a tubular shape that can be divided into equal parts.

5. **Exclusion of Other Phyla**:
- Other phyla such as Mollusca and Arthropoda typically exhibit bilateral symmetry, which means they cannot be classified under radial symmetry.

**Hint**: Recall that organisms like clams and insects have a distinct left and right side.

6. **Conclusion**:
- Therefore, the correct answer to the question "Radial symmetry is seen in" would be members of the phylum Cnidaria and certain sponges like Cycon and Leucosolenia.

### Final Answer:
Radial symmetry is seen in members of the phylum Cnidaria and certain tubular sponges like Cycon and Leucosolenia.