Euglena occurs in

Options

A. Sea
B. Fresh water
C. Both A and B
D. Moist soils.

Answer

**Step-by-Step Solution:**

1. **Understanding Euglena**: Euglena is a unicellular organism that belongs to the kingdom Protista. It exhibits characteristics of both plants and animals.

2. **Habitat of Euglena**: Euglena can be found in various environments. It thrives in both freshwater and marine (saltwater) habitats.

3. **Freshwater Sources**: Euglena is commonly found in freshwater sources such as rivers, lakes, and ponds.

4. **Marine Environments**: In addition to freshwater, Euglena can also occur in marine environments, which include oceans and seas.

5. **Conclusion**: Since Euglena is found in both freshwater and marine environments, the correct answer to the question "Euglena occurs in" is option C, which states "both A and B".

**Final Answer**: Option C (both A and B).

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