Answer:
B) nad+ and fad are regenerated
Explanation:
NAD+ and FAD serve as the electron acceptors for redox reactions of glycolysis and Kreb's cycle and are reduced into NADH and FADH2 respectively.
During oxidative phosphorylation, NADH and FADH2 donate their electrons to the terminal electron acceptor, the molecular oxygen via a chain of proteins embedded in the inner mitochondrial membrane.
Oxidation of NADH and FADH2 regenerates NAD+ and FAD so that they can enter the glycolysis and Kreb's cycle again.