What contributes the most to acid rain?

Options

A. Forest fires
B. Car Exhaust
C. Coal Power Plants
D. None of the above

Answer

**Step-by-Step Solution:**

1. **Understanding Acid Rain**: Acid rain refers to precipitation that is significantly more acidic than normal rainwater, primarily due to the presence of sulfuric and nitric acids.

2. **Identifying Sources of Acid Rain**: The main contributors to acid rain are gases like sulfur dioxide (SO2) and nitrogen oxides (NOx). These gases can be released into the atmosphere from various sources.

3. **Evaluating the Options**:
- **Forest Fire**: While forest fires can lead to deforestation and release some pollutants, they are not the primary contributors to acid rain.
- **Car Exhaust**: Car exhaust is a significant source of nitrogen oxides (NOx) and carbon dioxide (CO2). When fossil fuels are burned in vehicles, these gases are released into the atmosphere. NOx can react with water vapor in the atmosphere to form nitric acid, contributing to acid rain.
- **Coal Power Plants**: Coal combustion produces sulfur dioxide (SO2) and carbon dioxide (CO2). While SO2 can contribute to acid rain, the primary focus here is on the most significant contributor.
- **None of the Above**: This option is incorrect as we have identified contributors.

4. **Conclusion**: Among the options provided, car exhaust is the most significant contributor to acid rain due to the emission of nitrogen oxides which lead to the formation of nitric acid.

5. **Final Answer**: The correct answer is **car exhaust**.

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