Multiple choice

Which one of the following processes does not pollute air?

  1. Burning of dead wood

  2. Photosynthesis

  3. Use of cosmetics

  4. Use of insecticides

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Photosynthesis is a biological process where plants consume carbon dioxide and release oxygen, which helps clean the air rather than polluting it. The other options involve combustion or chemical release that contributes to pollution.