Acid rain is caused due to

Air pollution

The correct answer is Option (1) → Air pollution

Smoky fog over cities called as urban smog is caused by atmospheric pollution. It proves very harmful to human health. Air pollution can also cause acid rains.

Acid rain is a type of environmental pollution that is primarily caused by emissions of sulfur dioxide (SO₂) and nitrogen oxides (NOx) into the atmosphere. These pollutants are released into the air through various human activities, including the burning of fossil fuels such as coal, oil, and natural gas in industrial processes, power plants, and vehicles.