Yes, protons are pumped across the membrane, but flow right back again through the ATP synthase. More important is that illumination is required for carbon fixation. As photosynthesis runs, the chloroplasts remove CO2 from the water they are suspended in. In solution, CO2 forms carbonic acid, so removing CO2 will reduce the level of carbonic acid, raising the pH.
Answer: Well really the digestive, respiratory and circulatory systems all work together to make cellular respiration possible so i guess you could choose a or b
