Concept:Environmental pollution is caused by human activities that release harmful substances, while natural life-sustaining processes like photosynthesis do not pollute.
Explanation:Production of ammonia releases industrial waste gases that can pollute the air and water.
Manufacture of cement produces large amounts of dust and carbon dioxide
(CO2), which contribute to air pollution.
Combustion of fuels releases smoke, oxides, and other harmful gases into the environment.
Photosynthesis is the process by which green plants make their own food.
During photosynthesis, plants absorb
CO2 from the air and release oxygen
(O2) as a beneficial by-product.
Therefore, photosynthesis does not contribute to environmental pollution.
Answer:C. photosynthesis