When electrons flow along the electron transport chains of mitochondria, which statement is true
a) electrons from nadh get directly transferred to cyt c
b) nad+ and fad are regenerated
c) energy from atp hydrolysis is harvested for electron transport
d) the cytochromes phosphorylate adp to form atp
e) substrate level phosphorylation regulates atp synthesis

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.