Oriental sore is caused by

Options

A. Bacterium
B. Virus
C. Protozoan
D. Fungus

Answer

**Step-by-Step Solution:**

1. **Identify the Disease**: The question asks about the cause of "Oriental sore." This disease is also known as cutaneous leishmaniasis.

2. **Understand the Nature of the Disease**: Oriental sore is characterized by skin lesions, which can be ulcerative or glandular. These lesions often lead to facial redness and pigmentation changes, similar to those found in leprosy.

3. **Determine the Causative Agent**: The disease is caused by a unicellular organism. Specifically, it is caused by a protozoan parasite belonging to the genus *Leishmania*.

4. **Transmission Vector**: The disease is transmitted through the bite of a sand fly, which carries the protozoan parasite into the human host.

5. **Evaluate the Options**:
- Bacterium: Incorrect, as *Leishmania* is not a bacterium.
- Virus: Incorrect, as *Leishmania* is not a virus.
- Protozoan: Correct, as *Leishmania* is a protozoan.
- Fungus: Incorrect, as *Leishmania* is not a fungus.

6. **Conclusion**: The correct answer is that Oriental sore is caused by a protozoan, specifically from the genus *Leishmania*.

**Final Answer**: Oriental sore is caused by a protozoan.

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