Under aerobic conditions, the NADH formed during glycolysis A. is a waste product of glycolysis. B. converts acetaldehyde to ethanol and hence serves as the basis of many fermentation processes. C. has no metabolic advantage to the cell. D. provides additional energy by donating its electrons to the electron transport chain.

D. provides additional energy by donating its electrons to the electron transport chain.

Explanation:

In the presence of oxygen, NADH formed during glycolysis is oxidized and drives the synthesis of ATP by oxidative phosphorylation. Breakdown of glucose into pyruvate obtains two molecules of NADH. NADH is oxidized by giving its electrons to a terminal electron acceptor, the molecular oxygen.

Electron transfer from NADH to O2 occurs via electron transport chain and generates electrochemical gradient which in turn drives ATP synthesis. One NADH obtains around 3 molecules of ATP by oxidative phosphorylation.