'It is caused by a protozoan. It causes fever and can cause anaemia'.
The above information describes the disease named

Options

A. cholera
B. malaria
C. filariasis
D. hepatitis

Answer

To solve the question, we need to identify the disease described by the clues given: "It is caused by a protozoan. It causes fever and can cause anaemia."

### Step-by-Step Solution:

1. **Identify the Key Characteristics**:
- The disease is caused by a protozoan.
- It causes fever.
- It can lead to anaemia.

2. **Analyze the Options**:
- **Option A: Cholera**: This disease is caused by bacteria (Vibrio cholerae) and primarily affects the intestines. It does not match the characteristics since it is not caused by a protozoan.
- **Option B: Malaria**: This disease is caused by a protozoan (Plasmodium) and is transmitted by mosquitoes. It is known to cause fever and can lead to anaemia due to the destruction of red blood cells (RBCs).
- **Option C: Filariasis**: This disease is caused by parasitic worms, not protozoans, and does not typically cause anaemia.
- **Option D: Hepatitis**: This is a viral infection that primarily affects the liver and does not match the characteristics provided.

3. **Conclusion**:
- The only option that fits all the criteria (caused by a protozoan, causes fever, and can lead to anaemia) is **Option B: Malaria**.

### Final Answer:
The disease described is **Malaria**.

---