This is a tricky question. At first glance, there are two possible answer, B and D. But the thing is, D is incorrect because it states that photosynthesis occurs only in plants and that is not true since algae also use the same process.
→ So the answer is B because photosynthesis produces glucose which is stored but cellular respiration breaks down the glucose turning it into ATP.
Hope it helped,
BioTeacher101
