Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. The general equation for photosynthesis is:
\[
6CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2
\]
In this process:
- \( 6CO_2 \) represents carbon dioxide,
- \( 6H_2O \) represents water,
- \( C_6H_{12}O_6 \) is glucose (a form of sugar),
- \( 6O_2 \) is oxygen produced as a by-product.
Thus, the correct equation is Option (1).