The question is incomplete, so the complete question is as follows:
A chloroplast has stopped producing ATP and NADPH. Which of the following is most likely causing this?
a.The chloroplast has used up its supply of chlorophyll molecules.
b.Electrons have stopped moving through the electron transport chain.
c.The sun has risen and the chloroplast now can make more chlorophyll.
Answer:
b.Electrons have stopped moving through the electron transport chain.
Explanation:
ATP and NADPH are produced in the light dependent reaction stage of the photosynthesis that occurs within chloroplast grana.
ATP and NADPH are produced due to the movement of electron and proton (H+) in the electron transport chain, so if the movement of electrons will stopped in the electron transport chain, the formation of ATP and NADPH will also get stop.
Hence, the correct answer is "b".
