Hydra is

Options

A. Fresh water form, radially symmetrical and diploblastic
B. Marine, radially symmetrical and diploblastic
C. Fresh water form, bilaterally symmetrical and diploblastic
D. Marine, radially symmetrical and triploblastic

Explanation

To answer the question "Hydra is," we need to analyze the characteristics of Hydra based on three criteria: habitat, symmetry, and germ layers.

### Step-by-Step Solution:

1. **Identify the Habitat of Hydra**:
- Hydra is primarily found in **freshwater environments**. This means it lives in ponds, lakes, and streams rather than in marine (saltwater) habitats.

**Hint**: Remember that the habitat is the type of environment where an organism lives.

2. **Determine the Symmetry of Hydra**:
- The body symmetry of Hydra is **radial symmetry**. This means that if you were to draw lines through the center of Hydra, you could divide it into multiple equal halves, similar to slicing a pie.

**Hint**: Symmetry refers to how the body is organized; think about how many ways you can split the organism into equal parts.

3. **Identify the Germ Layers of Hydra**:
- Hydra is classified as a **diploblastic organism**, meaning it has two germ layers: the outer layer (epidermis) and the inner layer (gastrodermis or endodermis). There is no mesoderm present in diploblastic organisms.

**Hint**: Germ layers are the layers that form during embryonic development; diploblastic means two layers, while triploblastic means three layers.

### Conclusion:
Based on the above characteristics:
- Habitat: Freshwater
- Symmetry: Radial
- Germ Layers: Diploblastic

The correct answer is that Hydra is a freshwater organism with radial symmetry and is diploblastic.

### Final Answer:
Hydra is a freshwater organism, exhibits radial symmetry, and is diploblastic.