18. About the ATP production in the light reaction of photosynthesis, which one of the following is the best answer? (A)The concentration of H+ in the stroma is higher than thylakoid space during non-cyclic electron flow. (B) H+ can transport across membrane through plastocyanin (Pc) and ATP synthase. (C) H2O can continuously supply new H+ to elevate the H+ gradient between thylakoid membranes. (D)The final electron acceptor of non-cyclic electron flow is NADH reductase. (E)The ATP is produced inside the thylakoid space.