Intermediate between diploblastic and triploblastic body structure is found in

Options

A. Porifers
B. Coelenterates
C. Ctenophores
D. Platyhelminthes.

Answer

To answer the question regarding which organism has an intermediate body structure between diploblastic and triploblastic, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Diploblastic and Triploblastic Structures**:
- Diploblastic organisms have two germ layers: ectoderm and endoderm.
- Triploblastic organisms have three germ layers: ectoderm, mesoderm, and endoderm.

2. **Identifying Mesoglia**:
- Some diploblastic organisms possess a jelly-like substance called mesoglia, which lies between the ectoderm and endoderm. This is a key feature that indicates an intermediate structure.

3. **Analyzing the Options**:
- **Porifera**: These organisms are primarily considered diploblastic, as they lack true tissues and have only two layers.
- **Coelenterates (Cnidaria)**: These are also diploblastic organisms, consisting of ectoderm and endoderm, with no mesoderm or mesoglia.
- **Ctenophora (Stenophora)**: These organisms possess mesoglia, making them an intermediate between diploblastic and triploblastic.
- **Platyhelminthes**: These are triploblastic organisms, having all three germ layers and do not have mesoglia.

4. **Conclusion**:
- The only group among the options that exhibits an intermediate body structure with mesoglia is **Ctenophora (Stenophora)**.

### Final Answer:
The intermediate body structure between diploblastic and triploblastic is found in **Ctenophora**.

---