Cancer is

Options

A. Air borne
B. Viral disease
C. Environmental disorder
D. Cellular disease

Answer

### Step-by-Step Solution:

1. **Understanding Cancer**: Cancer is primarily characterized as a disease that involves the uncontrolled growth of abnormal cells in the body.

2. **Identifying the Type of Disease**: Among the options provided (airborne disease, viral disease, environmental disorder, cellular disease), we need to determine which best describes cancer.

3. **Defining Cellular Disease**: A cellular disease is one that originates at the cellular level, often involving changes in the normal functioning of cells, such as uncontrolled division and growth.

4. **Mechanism of Cancer Development**: Cancer cells are formed when normal cells undergo mutations that lead to rapid and uncontrolled mitosis (cell division). This can be triggered by various factors, including mutagens.

5. **Role of Mutagens**: Mutagens are agents that cause mutations in the DNA. These can include chemicals, radiation, and certain viruses. The mutations can lead to inheritable changes in the DNA, which may result in cancerous growth.

6. **Spread of Cancer**: Cancer can spread through the body via the blood or lymphatic system, allowing it to affect multiple tissues and organs.

7. **Conclusion**: Based on the characteristics and mechanisms of cancer, it can be concluded that cancer is best classified as a **cellular disease**.

### Final Answer:
Cancer is a **cellular disease**.

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