An example of major air pollutant is

Options

A. CO
B. Oxides of nitrogen
C. Oxides of sulphur
D. all .

Answer

To answer the question "An example of a major air pollutant is," we can follow these steps:

### Step-by-Step Solution:

1. **Identify Major Air Pollutants**:
- Major air pollutants include substances that significantly affect air quality and can harm human health and the environment. Common examples are carbon monoxide (CO), nitrogen oxides (NOx), and sulfur oxides (SO2).

2. **List the Examples**:
- **Carbon Monoxide (CO)**: A colorless, odorless gas produced by incomplete combustion of fossil fuels.
- **Nitrogen Oxides (NOx)**: This includes gases like nitric oxide (NO) and nitrogen dioxide (NO2), which are produced from vehicle emissions and industrial activities.
- **Sulfur Dioxide (SO2)**: A gas produced from burning fossil fuels containing sulfur, such as coal and oil.

3. **Explain the Impact**:
- These pollutants can react with water vapor in the atmosphere to form acids, leading to acid rain. For instance:
- CO can form carbonic acid (H2CO3).
- NOx can form nitric acid (HNO3).
- SO2 can form sulfuric acid (H2SO4).
- Acid rain can have detrimental effects on ecosystems, buildings, and human health.

4. **Conclusion**:
- Therefore, an example of a major air pollutant is carbon monoxide (CO), nitrogen oxides (NOx), or sulfur dioxide (SO2).

### Final Answer:
An example of a major air pollutant is **carbon monoxide (CO)**.

---