Man-made source of air pollution is

Options

A. volcanic eruptions
B. burning of fossil fuels
C. pollens
D. both (a) and (b).

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a man-made source of air pollution. This means we need to identify which option is caused by human activities.

2. **Analyzing the Options**:
- **Volcanic Eruptions**: These are natural events and not caused by humans.
- **Burning of Fossil Fuels**: This is a human activity where fossil fuels like coal, natural gas, and oil are burned for energy.
- **Pollens**: These are produced by plants and are not a result of human activities.
- **Both E and B**: This option is not relevant since we have already identified that only one of the options is man-made.

3. **Identifying the Man-Made Source**: The burning of fossil fuels is the only option that involves human intervention. Humans burn fossil fuels to generate heat and electricity, which leads to the emission of harmful gases.

4. **Understanding the Impact**: The burning of fossil fuels releases gases such as carbon dioxide and sulfur dioxide into the atmosphere. These gases contribute to air pollution and have various harmful effects, including global warming and respiratory issues.

5. **Conclusion**: Based on the analysis, the correct answer to the question is the "burning of fossil fuels."

### Final Answer:
The man-made source of air pollution is the **burning of fossil fuels**.

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