* Light-Dependent Reactions: These reactions occur in the thylakoid membranes of chloroplasts. They use light energy to:

* Split water molecules, releasing oxygen (D).

* Generate ATP (C) through photophosphorylation.

* Produce NADPH (A) by reducing NADP+.

* Light-Independent Reactions (Calvin Cycle): This is where sugars (B) are produced. The ATP and NADPH generated in the light-dependent reactions power the Calvin cycle, which uses carbon dioxide from the atmosphere to build glucose (a type of sugar).

In summary: The light-dependent reactions provide the energy (ATP) and reducing power (NADPH) needed for the Calvin cycle to synthesize sugars.