Answer:
B. Carbon dioxide
Step-by-step explanation:
B. Carbon dioxide is the source of carbon atoms used by plants to create glucose molecules.
Plants absorb carbon dioxide from the atmosphere during photosynthesis and use a process known as carbon fixation to turn it into glucose. After that, the glucose is put to use as a fuel source or as a component of other molecules including sucrose, cellulose, and starch. In order to move energy from the light-dependent processes to the light-independent reactions, where carbon fixation takes place, photosynthesis uses the energy carrier molecules NADPH (nicotinamide adenine dinucleotide phosphate) and ADP (adenosine diphosphate).