Diseases are broadly grouped into infectious and non-infectious deseases. In the list given below, identify the infectious diseases.
(i) Cancer , (ii) Influenza
(iii) Allergy, (iv) Small pox

Options

A. I and II
B. II and III
C. III and IV
D. II and IV

Explanation

To identify the infectious diseases from the given list, we will analyze each option based on their characteristics:

1. **Cancer**:
- Cancer is characterized by the uncontrolled growth of abnormal cells in the body. It does not spread from person to person; rather, it originates from changes in the cells of an individual. Therefore, cancer is classified as a **non-infectious disease**.

2. **Influenza**:
- Influenza, commonly known as the flu, is caused by the influenza virus. It is highly contagious and can spread easily from one person to another through respiratory droplets when an infected person coughs or sneezes. Thus, influenza is classified as an **infectious disease**.

3. **Allergy**:
- Allergies are immune responses to certain substances (allergens) such as pollen, dust, or certain foods. They do not involve pathogens and are not transmitted from person to person. Therefore, allergies are classified as **non-infectious diseases**.

4. **Smallpox**:
- Smallpox is a viral infection caused by the variola virus. It is highly contagious and spreads through direct contact with infected individuals or contaminated materials. Hence, smallpox is classified as an **infectious disease**.

**Conclusion**:
Based on the analysis, the infectious diseases from the list are:
- **Influenza**
- **Smallpox**