Which of the following is an important difference between light-dependent and light-independent reactions of photosynthesis? the light-dependent reactions occur only during the day; the light-independent reactions occur only during the night. a the light-dependent reactions occur in the cytoplasm; the light-independent reactions occur in chloroplasts. b the light-dependent reactions utilize co2 and h2o; the light-independent reactions produce co2 and h2o. c the light-dependent reactions depend on the presence of both photosystems i and ii; the light-independent reactions require only photosystem i. d the light-dependent reactions produce atp and nadph; the light-independent reactions use energy stored in atp and nadph.