Answer:
The correct answer would be "Photosynthesis produces oxygen, while cellular respiration produces carbon dioxide"
Photosynthesis refers to the process by which plants make their food (sugars or glucose) from carbon dioxide and water with the help of sunlight and chlorophyll.
It takes place in chloroplast of the cell. Oxygen is released as the byproduct of the process.
The whole reaction can be summarized as:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
In contrast, cellular respiration refers to the set of chemical reactions which take place in the cell in order to convert the chemical energy of the food (sugar) into ATP.
Carbon dioxide is released as the byproduct.
The whole reaction can be summarized as
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O