Solution: Inside thylakoids, light processes take place. It is dependent on the presence of light. It involves water photolysis (the splitting of water into H 2 and O 2 and the generation of assimilation power) (NADPH and ATP). The P 680 photo center of photosystem II picks up an electron produced during water photolysis. Electrons move through a variety of carriers, including PQ, the cytochrome b-f complex, and PC. The electron loses enough energy while passing through the cytochrome complex to create a proton gradient and ATP from ADP and inorganic phosphate. From PC, enough energy is lost to create a proton gradient and ATP from ADP and inorganic phosphate. The trap center P 700 of photosystem I picks up electrons from PC and pushes them out after absorbing light energy. The electron goes through the carriers Fes, ferredoxin, and NADP reductase, which gives an electron to NADP, which then combines with H to form NADPH.

So, the correct answer is (a).