Choose the correct pair.

Options

A. Radial symmetry - Coelenterates
B. Coelomates - Aschelminthes
C. Metamerism -Molluscs
D. Triploblastic -Sponges

Answer

To solve the question "Choose the correct pair," we need to analyze each option provided and determine if the pairings are accurate based on biological classifications.

### Step-by-Step Solution:

1. **Identify the first pair: Radial symmetry and Cnidarians (Coelenterates)**
- Radial symmetry refers to organisms that have body parts arranged around a central axis. Cnidarians, such as jellyfish and sea anemones, exhibit radial symmetry.
- **Conclusion**: This pair is correct.

2. **Identify the second pair: Coelomate and Acoelomate**
- Coelomates are animals that possess a true coelom (body cavity), while acoelomates do not have a body cavity. The term "Escalement" seems to be a misinterpretation; it may refer to "Acoelomate."
- **Conclusion**: This pairing is incorrect as it conflates two different classifications.

3. **Identify the third pair: Metamerism and Mollusks**
- Metamerism refers to the segmentation of the body into repeated units. Mollusks do not exhibit metamerism; this characteristic is more associated with annelids (segmented worms).
- **Conclusion**: This pairing is incorrect.

4. **Identify the fourth pair: Triploblastic and Sponges**
- Triploblastic organisms have three germ layers (ectoderm, mesoderm, and endoderm). Sponges, however, are classified as diploblastic (having only two germ layers).
- **Conclusion**: This pairing is incorrect.

### Final Conclusion:
The only correct pair is the first one: **Radial symmetry and Cnidarians (Coelenterates)**.