oof that''s actually pretty tough cause a plant need all of those but photosynthesis is the process of making the food.
water- plant can drink
oxygen-plant gives off
glucose- that's what the food is made of which seems like the best answer
and
calcium- honestly i don't really know about this but i think that's what makes the plant strong along side it's food and water
i'm pretty sure the answer is glucose, hopefully i helped lol