The correct chemical equation that represents photosynthesis is:
A. Carbon dioxide plus water yields glucose and oxygen.
In the process of photosynthesis, plants use carbon dioxide (CO2) and water (H2O) to produce glucose (C6H12O6) and oxygen (O2) in the presence of sunlight. The overall reaction can be summarized by the equation:
\[ \text{6 CO}_2 + \text{6 H}_2\text{O} + \text{light energy} \rightarrow \text{C}6\text{H}{12}\text{O}_6 + \text{6 O}_2 \]