Which out of the following is NOT a source of water pollution?

The correct answer is Option (3) → Combustion of coal

Option (1) Sewage Disposal — A source of water pollution (Incorrect). Sewage carries human waste into rivers and lakes, so sewage disposal is a source of water pollution, not of air pollution.

Option (2) Urban run-off — A source of water pollution (Incorrect). Run-off from towns carries dirt and waste into water bodies.

Option (3) Combustion of coal — Not a source of water pollution (Correct). Combustion of coal, petrol and diesel is a source of air pollution: burning releases oxides of sulphur and nitrogen, carbon monoxide and other gases into the air.

Option (4) Run-off over cultivated lands — A source of water pollution (Incorrect). Water flowing off farms carries fertiliser and pesticide residue into rivers and raises their nitrate content.

Note: A similar question was also asked in CUET (UG) 2025 on 14-05-2025 (Slot 2).