Nutritionally, protists are-

Options

A. Photoautotrophs
B. Heterotrophs
C. Mixotrophs
D. Photoautotrophs, heterotrophs or autotrophs

Answer

### Step-by-Step Solution:

1. **Understanding Protists**:
- Protists are a diverse group of eukaryotic microorganisms that can be found in various environments. They belong to the kingdom Protista and include organisms that are not classified as plants, animals, or fungi.

2. **Nutritional Modes**:
- Nutritionally, protists can be categorized based on how they obtain their food. The main nutritional modes are:
- **Photoautotrophs**: These organisms can synthesize their own food using light energy through the process of photosynthesis. They contain chlorophyll and are capable of converting light energy into chemical energy.
- **Heterotrophs**: These organisms cannot produce their own food and must obtain it by consuming other organisms. They can be further classified into:
- **Saprophytic**: Feeding on dead organic matter.
- **Parasitic**: Feeding on a host organism, often harming it in the process.
- **Mixotrophs**: These organisms can switch between autotrophic and heterotrophic modes depending on environmental conditions.

3. **Conclusion**:
- Therefore, protists can be photoautotrophs, heterotrophs, or mixotrophs. This means that they can synthesize their own food, depend on other organisms for food, or do both depending on the circumstances.

4. **Correct Answer**:
- The correct answer to the question "Nutritionally, protists are" is **Photoautotrophs, Heterotrophs, and Mixotrophs**.