Answer: A. splitting water into hydrogen and oxygen
Step-by-step explanation:
Photosynthesis is the process by which plants produce glucose by reacting carbon dioxide and water in the presence of sunlight. Chlorophyll which gives the plant its green color, traps sunlight and uses it to split water molecules into their constituent molecules of hydrogen and oxygen.
Glucose is then synthesized from these molecules and used in respiration to release energy for the plant.