Plant body is a photosynthetic filament in

Options

A. Riccia
B. Chlamydomonas
C. Spirogyra
D. Pteris.

Answer

To answer the question "Plant body is a photosynthetic filament in", we need to analyze the given options and identify which one describes a plant body that is filamentous and photosynthetic.

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for a plant body that is a photosynthetic filament. This means we are looking for an organism that has a filamentous structure and is capable of photosynthesis.

2. **Evaluate the First Option: Riccia**:
- Riccia is a type of bryophyte.
- Its plant body is not filamentous; instead, it is thalloid, which means it does not have true roots, stems, or leaves.
- Therefore, Riccia does not fit the criteria of being a photosynthetic filament.

3. **Evaluate the Second Option: Chlamydomonas**:
- Chlamydomonas is a unicellular green alga.
- It is not filamentous; it exists as a single cell.
- Thus, Chlamydomonas also does not meet the requirement of being a filamentous plant body.

4. **Evaluate the Third Option: Spirogyra**:
- Spirogyra is a green alga known for its filamentous structure.
- It is unbranched and forms mucilaginous filaments that float in freshwater bodies.
- Spirogyra is indeed a photosynthetic filament, making it the correct answer.

5. **Evaluate the Fourth Option: Other Options**:
- The other options mentioned (like Dryopteris) do not have a filamentous structure either.
- They may be part of the plant kingdom and perform photosynthesis, but they do not fit the description of a filamentous body.

6. **Conclusion**: Based on the evaluations, the correct answer to the question is Spirogyra, as it is the only option that describes a plant body that is a photosynthetic filament.

### Final Answer:
The plant body is a photosynthetic filament in **Spirogyra**.