Which of the following is not an infectious disease ?

Options

A. AIDS
B. Cancer
C. Hepatitis-B
D. Typhoid

Answer

To determine which of the following options is not an infectious disease, we need to understand the definitions and causes of each disease listed. Infectious diseases are caused by pathogens such as bacteria, viruses, fungi, or parasites. Let's analyze each option step by step:

1. **AIDS**:
- AIDS (Acquired Immunodeficiency Syndrome) is caused by the Human Immunodeficiency Virus (HIV).
- Since HIV is a virus, AIDS is classified as an infectious disease.

2. **Cancer**:
- Cancer is not caused by any infectious agent. Instead, it results from mutations in the cells of the body.
- These mutations can be triggered by various factors such as genetic predisposition, environmental influences, and lifestyle choices, but they are not caused by bacteria, viruses, fungi, or parasites.
- Therefore, cancer is not an infectious disease.

3. **Hepatitis B**:
- Hepatitis B is caused by the Hepatitis B virus (HBV).
- Since it is caused by a virus, Hepatitis B is classified as an infectious disease.

4. **Typhoid**:
- Typhoid fever is caused by the bacterium Salmonella typhi.
- As it is caused by bacteria, typhoid is also classified as an infectious disease.

Based on this analysis, the only option that is not an infectious disease is **Cancer**.

### Summary:
- **AIDS**: Infectious disease (caused by HIV).
- **Cancer**: Not an infectious disease (caused by cell mutations).
- **Hepatitis B**: Infectious disease (caused by Hepatitis B virus).
- **Typhoid**: Infectious disease (caused by Salmonella typhi).

**Final Answer**: Cancer is not an infectious disease.