Acid rain is caused by increase in the atomospheric concentration of

Options

A. `SO_(2)` and `NO_(2)`
B. `SO_(3)` and `CO`
C. `CO_(2)` and `CO`
D. `O_(3)` and dust

Answer

### Step-by-Step Solution:

1. **Understanding Acid Rain**:
- Acid rain refers to any precipitation (rain, snow, sleet, or hail) that has a pH level lower than 5. This indicates that it is more acidic than normal rainwater.

2. **Identifying Causes of Acid Rain**:
- The primary contributors to acid rain are sulfur dioxide (SO2) and nitrogen oxides (NO2). These compounds are released into the atmosphere through various human activities, such as burning fossil fuels.

3. **Chemical Reactions**:
- Once in the atmosphere, sulfur dioxide and nitrogen oxides undergo chemical reactions.
- Sulfur dioxide can react with oxygen and water vapor to form sulfuric acid (H2SO4).
- Nitrogen oxides can react with oxygen and water to form nitric acid (HNO3).

4. **Formation of Acid Rain**:
- The acids formed (sulfuric acid and nitric acid) then mix with the moisture in the atmosphere and fall to the ground as acid rain.

5. **Conclusion**:
- Based on the above information, the correct answer to the question "Acid rain is caused by increase in the atmospheric concentration of" is **option A: SO2 and NO2**.