When any plane passing through the central axis of the of the body divides the organism into two identical halves, it is radial symmetry. Which of the following set of animals has radial symmetry ?

Options

A. Housefly, fish , human being
B. Sponges, hydra, carbs
C. Coelenterates, ctenophores, echinoderms
D. Annelids, arhtropods, housefly

Answer

To determine which set of animals has radial symmetry, we need to analyze the options provided and identify the symmetry type of each organism mentioned.

### Step-by-Step Solution:

1. **Understand Radial Symmetry**:
- Radial symmetry means that an organism can be divided into identical halves by multiple planes passing through the central axis. This is common in organisms that are typically sessile or free-floating.

2. **Analyze the Options**:
- **Option A**: Housefly, Fish, Human
- Housefly belongs to the phylum Arthropoda (bilateral symmetry).
- Fish and humans belong to the phylum Chordata (bilateral symmetry).
- **Conclusion**: All these organisms exhibit bilateral symmetry.

- **Option B**: Sponges, Hydra, Crab
- Sponges belong to the phylum Porifera (radial symmetry).
- Hydra belongs to the phylum Cnidaria (radial symmetry).
- Crab belongs to the phylum Arthropoda (bilateral symmetry).
- **Conclusion**: Only sponges and hydra exhibit radial symmetry, while crab does not.

- **Option C**: Cnidarians, Ctenophores, Echinoderms
- Cnidarians (e.g., jellyfish, corals) exhibit radial symmetry.
- Ctenophores (e.g., comb jellies) also exhibit radial symmetry.
- Echinoderms (e.g., starfish, sea urchins) exhibit radial symmetry as adults.
- **Conclusion**: All these organisms exhibit radial symmetry.

- **Option D**: Nematodes, Arthropoda, Housefly
- Nematodes belong to the phylum Nematoda (bilateral symmetry).
- Arthropoda includes various organisms like insects and crustaceans (bilateral symmetry).
- Housefly, as previously mentioned, is also bilateral.
- **Conclusion**: All these organisms exhibit bilateral symmetry.

3. **Final Conclusion**:
- The only option that contains organisms with radial symmetry is **Option C: Cnidarians, Ctenophores, and Echinoderms**.

### Answer:
**Option C: Cnidarians, Ctenophores, and Echinoderms** have radial symmetry.