Answer:
a
Step-by-step explanation:
basically to remember this, plants take in carbon and release oxygen; the opposite as humans. and for the second part water is needed to produce glucose. the formal definition is "glucose is made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, which is the most abundant carbohydrate." im sorry if this isnt best explanation but i wanted to make sure someone answered your question