Answer: B (photosynthesis). Photosynthesis is the process in which green plants take in carbon dioxide and water and, using light energy, convert them into glucose and oxygen. Because it consumes carbon dioxide, photosynthesis removes CO₂ from the atmosphere, which is its role in the carbon cycle.
The other processes all add carbon dioxide to the atmosphere rather than removing it, so each is the opposite of what the question asks. Combustion of fuels releases CO₂ as carbon-containing fuels burn in oxygen. Respiration releases CO₂ as living organisms break down glucose to release energy. Volcanic activity also emits large amounts of CO₂ into the air from deep within the Earth.
Within the carbon cycle, only photosynthesis takes carbon dioxide out of the atmosphere, balancing the CO₂ added by the other three processes, so the answer is B.
Every O Level Pure Chemistry TYS MCQ solution video, plus full Sec 3 / Sec 4 topic recordings.
Find out more