The correct answer is A. H2O.
Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar. The chemical equation for photosynthesis is:
6CO2 + 6H2O + light energy â C6H12O6 + 6O2
As you can see from the equation, the oxygen released during photosynthesis comes from water (H2O). The carbon dioxide (CO2) is used to create glucose (C6H12O6), which is a type of sugar. The light energy is used to power the process.
Option B, CO2, is incorrect because CO2 is used as a reactant in photosynthesis, not as a product. Option C, NO2, is incorrect because NO2 is not a reactant or product in photosynthesis. Option D, glucose, is incorrect because glucose is a product of photosynthesis, not a reactant.