Locomotive structures found in some protists include

Options

A. muscles
B. flagella
C. tentacles
D. contractile vacuoles.

Explanation

### Step-by-Step Solution:

1. **Understanding Protists**:
- Protists are a diverse group of unicellular eukaryotic organisms. They can be found in various environments and can be photosynthetic or non-photosynthetic.

2. **Identifying Locomotive Structures**:
- The locomotion in protists is facilitated by specialized structures. The main locomotive structures found in some protists include:
- **Cilia**: These are short, hair-like structures that cover the surface of some protists, such as Paramecium, and help in movement.
- **Flagella**: These are longer, whip-like structures that some protists, like Euglena, use to propel themselves through water.
- **Pseudopodia**: These are temporary, foot-like extensions of the cell membrane and cytoplasm, used by organisms like Amoeba for movement and feeding.

3. **Examples of Protists with Locomotive Structures**:
- **Cilia**: Found in Paramecium.
- **Flagella**: Found in Euglena.
- **Pseudopodia**: Found in Amoeba.

4. **Conclusion**:
- The locomotive structures found in some protists include cilia, flagella, and pseudopodia.