Atmospheric carbon dioxide balance is most closely linked with which processes?

Correct answer: Photosynthesis, respiration, combustion and oceanic absorption

Direct answer: C is correct. Atmospheric carbon dioxide is controlled by exchanges in the carbon cycle. Green plants remove carbon dioxide during photosynthesis and use it to make organic food. Respiration by plants, animals and microorganisms returns some carbon dioxide to the air, while decomposition also releases it. Combustion of fuels and biomass adds carbon dioxide rapidly. Oceans absorb and release carbon dioxide, with the exchange affected by conditions such as temperature and concentration. These processes together influence the atmospheric balance. A is wrong because tides and earthquakes are not the principal natural exchange processes listed here. B concerns unrelated phenomena. D describes astronomical events or objects, not carbon exchange. Therefore C is the only option linking the major biological, chemical and physical processes.