Answer:
B. The chloroplasts will generate less ATP.
Step-by-step explanation:
The pumping of hydrogen ions in the electron transport chain creates a proton gradient, with a high concentration of hydrogen ions in the lumen. The potential energy of the gradient is then used to combine ADP to phosphate, creating ATP. If the thylakoid membranes were permeable to hydrogen ions, a proton gradient would not be established, thus there would be no potential energy to synthesize ATP, and less ATP would be generated by the chloroplasts.