All eukaryotic unicellular organisms belong to

Options

A. Monera
B. Protista
C. Fungi
D. Bacteria

Answer

To solve the question "All eukaryotic unicellular organisms belong to," we will analyze the options provided and determine the correct classification.

### Step-by-Step Solution:

1. **Understanding Eukaryotic Organisms**:
- Eukaryotic organisms are those that have a defined nucleus and membrane-bound organelles. This is a key characteristic that distinguishes them from prokaryotic organisms, which lack a defined nucleus.

2. **Identifying Unicellular Organisms**:
- Unicellular organisms are those that consist of a single cell. While there are both prokaryotic and eukaryotic unicellular organisms, we are specifically looking for eukaryotic ones.

3. **Analyzing the Options**:
- **Option A: Monera**: This kingdom includes prokaryotic organisms, such as bacteria, and is not relevant to eukaryotic unicellular organisms.
- **Option B: Protista**: This kingdom is primarily composed of eukaryotic unicellular organisms, such as protozoa and some algae. This is a strong candidate for our answer.
- **Option C: Fungi**: While fungi can include unicellular organisms (like yeast), they are primarily multicellular and are not classified under eukaryotic unicellular organisms as a whole.
- **Option D: Bacteria**: Like Monera, bacteria are prokaryotic and therefore do not fit the criteria of eukaryotic unicellular organisms.

4. **Conclusion**:
- Based on the analysis, all eukaryotic unicellular organisms belong to **Option B: Protista**. This kingdom is specifically known for its diverse group of unicellular eukaryotic organisms.

### Final Answer:
All eukaryotic unicellular organisms belong to **Option B: Protista**.