The correct answer is - Its electrons are used to form NADPH.
On receiving light energy, electrons are expelled from the reaction center of photosystem II. The expelled electrons finally reduces oxidized NADH⁺ to NADH. The oxidized reaction center of photosystem II split water into protons, electrons and oxygen. The electrons released from water reduces oxidized reaction center of photosystem II. Thus, oxidized reaction center of photosystem II gets back its expelled electrons. Therefore, electrons from water forms NADH.