Protozoans are single-celled animals.

Answer

### Step-by-Step Solution:

1. **Definition of Protozoans**: Protozoans are classified as single-celled organisms, which means they consist of only one cell. This characteristic classifies them as unicellular animals.

2. **Example of Protozoans**: A common example of a protozoan is Amoeba. Amoeba is a unicellular organism, meaning it is made up of a single cell.

3. **Cell Structure**: Protozoans, including Amoeba, are categorized as eukaryotes. This classification is due to the presence of a well-developed nucleus and a nuclear membrane within the cell.

4. **Mode of Nutrition**: Protozoans are heterotrophic, meaning they cannot produce their own food. Instead, they obtain nutrition by consuming organic matter from their environment.

5. **Conclusion**: Therefore, it is correct to say that protozoans are single-celled animals, as they are unicellular eukaryotic organisms that exhibit heterotrophic nutrition.