Assertion(A): Burning of fossil fuels is harmful to humans, animals, and plants.
Reason(R): These air pollutants must be removed to keep our air clean.
1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true.