The chemical equation shown represents photosynthesis. Carbon dioxide plus A plus light with a right-pointing arrow towards B plus oxygen. The arrow has an x above it.

What is the role of substance A in photosynthesis?

A. It stores chemical energy for plants and animals.
B. It traps light energy and converts it into chemical energy.
C. It combines with carbon dioxide and light to form glucose.
D. It combines with carbon dioxide and light to form hydrogen.