What is the overall purpose of the electron transport chain in cellular respiration?

What is the overall purpose of the electron transport chain in cellular respiration?

A.) NAD+ and FAD come from glycolysis and the citric acid cycle to the electron transport chain (ETC). They release their high energy electrons. The electrons flow down the ETC to make a hydrogen gradient. The hydrogen gradient flows through ATP synthase to add a phosphate onto ADP to make lots of ATP.

B.) NADH and FADH2 come from glycolysis and the citric acid cycle to the electron transport chain (ETC). They release their high energy electrons. The electrons flow down the ETC to make a hydrogen gradient. The hydrogen gradient flows through ATP synthase to add a phosphate onto ADP to make a little ATP.

C.) NAD+ and FAD come from glycolysis and the citric acid cycle to the electron transport chain (ETC). They release their high energy electrons. The electrons flow down the ETC to make a hydrogen gradient. The hydrogen gradient flows through ATP synthase to add a phosphate onto ADP to make a little ATP.

D.) NADH and FADH2 come from glycolysis and the citric acid cycle to the electron transport chain (ETC). They release their high energy electrons. The electrons flow down the ETC to make a hydrogen gradient. The hydrogen gradient flows through ATP synthase to add a phosphate onto ADP to make lots of ATP.