Air borne diseases are
A. influenza
B. typhoid
C.tuberculosis
D. diarrhoea

Options

A. A,C
B. B,C
C. C,D
D. A,D

Answer

To determine which diseases from the given options are airborne diseases, we will analyze each option based on how they spread.

### Step-by-Step Solution:

1. **Understanding Airborne Diseases**:
- Airborne diseases are illnesses that can be transmitted through the air, typically via respiratory droplets that are expelled when an infected person sneezes, coughs, or talks.

2. **Analyzing Option A: Influenza**:
- Influenza is indeed a viral infection that spreads through respiratory droplets. Therefore, it is considered an airborne disease.

3. **Analyzing Option B: Typhoid**:
- Typhoid fever is primarily transmitted through contaminated food and water, not through the air. Thus, it is not classified as an airborne disease.

4. **Analyzing Option C: Tuberculosis**:
- Tuberculosis (TB) is a bacterial infection that spreads through the air when an infected person coughs or sneezes. Therefore, it is classified as an airborne disease.

5. **Analyzing Option D: Diarrhoea**:
- Diarrhoea is usually caused by infections from contaminated food or water and is not spread through the air. Hence, it is not an airborne disease.

6. **Conclusion**:
- From the analysis, the diseases classified as airborne are **Influenza** and **Tuberculosis**. Therefore, the correct options from the list are **A (Influenza)** and **C (Tuberculosis)**.

### Final Answer:
The airborne diseases from the options provided are:
- A. Influenza
- C. Tuberculosis