Which of the following compounds is reduced in the following chemical reaction?
\(6CO_2+6H_2O \longrightarrow C_6H_{12}O_6+6O_2\)

This is the equation for photosynthesis. In photosynthesis, the carbon dioxide is reduced (gains electrons) to become glucose. The oxidation number of carbon in carbon dioxide is +4, however the oxidation number of carbon in glucose is 0, therefore the carbon gains 4 electrons to reduce its oxidation number.[Earth and Physical Science]