Which of the following is a water borne disease?

Options

A. Dengue
B. Malaria
C. Tuberculosis
D. Cholera

Explanation

### Step-by-Step Solution:

1. **Identify the Diseases**: The question provides four diseases: dengue, malaria, tuberculosis, and cholera.

2. **Analyze Each Disease**:
- **Dengue**: This is a viral infection spread by mosquitoes. It is not waterborne.
- **Malaria**: This is caused by the protozoan Plasmodium and is also spread by mosquitoes. It is not waterborne.
- **Tuberculosis**: This is a bacterial infection that primarily affects the lungs and is spread through airborne droplets. It is not waterborne.
- **Cholera**: This is a bacterial disease caused by Vibrio cholerae. It primarily affects the small intestine and is spread through contaminated water and food.

3. **Determine the Waterborne Disease**: Among the diseases analyzed, cholera is the only one that is spread through contaminated water.

4. **Conclusion**: The correct answer to the question "Which of the following is a waterborne disease?" is cholera.

### Final Answer:
Cholera is a waterborne disease.

---