Respiration is the process in which energy is released from the oxidation of glucose in the cell which is converted in the form of ATP. During this respiration process CO₂ and H₂O is released as a byproduct of the process.
This carbon dioxide is released in the atmosphere which is taken by green plants for photosynthesis process. In respiration process, one molecule of glucose gives rise to 6 molecules of CO₂ and 6 molecules of H₂O.
This is a exergonic process in which energy is released. Some energy is lost as heat and some energy is used to form new source of energy in the form of ATP. So the right answer is CO2 and H2O.
