A bacterial disease is

Options

A. Amoebic dysentery
B. Beri-beri
C. Leprosy
D. Arthritis.

Answer

### Step-by-Step Solution:

1. **Identify the options provided**: The question lists four options:
- A) Amoebic dysentery
- B) Beriberi
- C) Leprosy
- D) Arthritis

2. **Analyze each option**:
- **Option A: Amoebic dysentery** - This disease is caused by a protozoan parasite known as *Entamoeba histolytica*. Since it is not caused by bacteria, this option is incorrect.

- **Option B: Beriberi** - This condition is a result of a deficiency in vitamin B1 (thiamine). It is not caused by bacteria, making this option also incorrect.

- **Option C: Leprosy** - This disease is caused by the bacterium *Mycobacterium leprae*. Since it is caused by bacteria, this option is a potential correct answer.

- **Option D: Arthritis** - This is primarily a metabolic disorder and is not caused by bacteria. Therefore, this option is incorrect.

3. **Determine the correct answer**: Based on the analysis, the only disease caused by bacteria among the options provided is leprosy, caused by *Mycobacterium leprae*.

4. **Conclude the answer**: The correct answer to the question "A bacterial disease is" is **C) Leprosy**.