Concept:Photosynthesis is the only process among the options that releases oxygen into the atmosphere.Explanation:Green plants use light energy to convert carbon dioxide and water into glucose and oxygen.The balanced equation is:6CO2+6H2OlightC6H12O6+6O2Respiration, combustion, and decomposition all release carbon dioxide or consume oxygen instead.Therefore, oxygen is released to the atmosphere through photosynthesis.Answer:D. Photosynthesis