The correct statement is:
Water is required for the light-dependent reactions, and carbon dioxide is required for the light-independent reactions.
In photosynthesis, the light-dependent reactions occur in the thylakoid membranes of the chloroplasts and require water as a source of electrons and protons. These reactions produce oxygen as a byproduct. The light-independent reactions (Calvin cycle), which take place in the stroma of the chloroplasts, utilize carbon dioxide to synthesize glucose.