Acid rain occurs above the areas where :

Options

A. There is excess release of `NH_(3)` and coal gas
B. Factories are expelling `SO_(2)` into air
C. There is excess production of `CO_(2)` due to excessive combustion and respiration
D. There is excess production of gaseous hydrocarbons

Answer

**Step-by-Step Solution:**

1. **Understanding Acid Rain**: Acid rain is a type of precipitation that contains high levels of sulfuric and nitric acids. It occurs when sulfur dioxide (SO2) and nitrogen oxides (NOx) are released into the atmosphere and react with water, oxygen, and other chemicals.

2. **Identifying Sources of Acid Rain**: The primary sources of sulfur dioxide and nitrogen oxides are industrial activities, particularly from factories that burn fossil fuels. These emissions can lead to the formation of acid rain.

3. **Analyzing the Options**:
- Option 1: Excess release of NH3 and coal gas - While ammonia can contribute to air pollution, it is not a primary cause of acid rain.
- Option 2: Factories are expelling SO2 into the air - This is a significant contributor to acid rain, as SO2 reacts with water to form sulfuric acid.
- Option 3: Excess production of carbon dioxide due to combustion and respiration - CO2 contributes to the greenhouse effect but is not a direct cause of acid rain.
- Option 4: Excess production of gaseous hydrocarbons - Hydrocarbons can contribute to air pollution but are not directly linked to acid rain formation.

4. **Conclusion**: Based on the analysis, the correct answer is that acid rain occurs above areas where factories are expelling SO2 into the air. This is because the presence of sulfur dioxide leads to the formation of sulfuric acid when it reacts with atmospheric moisture.

**Final Answer**: Acid rain occurs above the areas where factories are expelling SO2 into the air.

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