Which statement accurately describes what occurs in photosystem II? Group of answer choices Light energy excites electrons in the electron transport chain in a photosynthetic unit. The photons are passed along to a molecule of P700 chlorophyll in the photosynthetic unit. The P680 chlorophyll donates a pair of protons to NADPH, which is thus converted to NADP+. The electron vacancies in P680 are filled by electrons derived from the splitting of water. The splitting of water yields molecular carbon dioxide as a by-product.