Assertion (A) : The pH of acid rain is less than 5.6.
Reason (R) : Carbon dioxide present in the atmosphere dissolves in rain water and forms carbonic acid.

Options

A. Both A and R are correct and R is the correct explanation of A
B. Both A and R are correct and R is not the correct explanation of A
C. Both A and R are not correct
D. A is not correct but R is correct

Explanation

**Step-by-Step Solution:**

1. **Understanding Acid Rain**:
- Acid rain is defined as rainwater that has a pH lower than 5.6. This is due to the presence of acidic components in the rainwater.

2. **Assertion Analysis**:
- The assertion states that the pH of acid rain is less than 5.6. This is true because acid rain is characterized by its lower pH.

3. **Reason Analysis**:
- The reason provided states that carbon dioxide (CO2) in the atmosphere dissolves in rainwater to form carbonic acid (H2CO3). This is also true as CO2 reacts with water to form carbonic acid.

4. **Formation of Acid Rain**:
- While carbon dioxide contributes to the acidity of rainwater, other pollutants like nitrogen dioxide (NO2) and sulfur dioxide (SO2) also contribute by forming nitric acid (HNO3) and sulfuric acid (H2SO4), respectively.

5. **Conclusion**:
- Both the assertion and reason are correct. However, the reason does not fully explain the assertion because it omits the contributions of other acids formed from different pollutants. Therefore, the assertion is correct, the reason is correct, but the reason is not the correct explanation for the assertion.

6. **Final Answer**:
- The correct option is B: Both assertion and reason are correct, but the reason is not the correct explanation of the assertion.

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