Pneumatophore is present in

Options

A. Hydra
B. Obelia
C. Physalia
D. Aurelia

Answer

To answer the question "Pneumatophore is present in," we will analyze the options provided and identify which organism contains pneumatophores.

### Step-by-Step Solution:

1. **Understand the Term "Pneumatophore":**
- A pneumatophore is a specialized structure that helps in buoyancy and floating. It is typically found in certain colonial organisms.

2. **Identify the Organisms in the Options:**
- The options provided are Hydra, Ophelia, Physalia, and Apia.
- All these organisms belong to the phylum Cnidaria.

3. **Analyze Each Organism:**
- **Hydra:** This is a solitary polyp and does not possess pneumatophores.
- **Ophelia:** This organism exhibits alternation of generations between polyp and medusa forms but does not have pneumatophores.
- **Physalia:** Commonly known as the Portuguese man-of-war, it is a colonial organism that consists of different types of polyps, including the pneumatophore, which serves as a float.
- **Apia:** This option does not correspond to a known organism in the context of Cnidaria and is likely a typographical error or misrepresentation.

4. **Conclusion:**
- Based on the analysis, the organism that possesses pneumatophores is **Physalia**.

### Final Answer:
Pneumatophore is present in **Physalia**.