Which of the Following Indicates a Primary Path by Which

Which of the following indicates a primary path by which electrons travel downhill energetically during aerobic respiration?

A) glucose → citric acid cycle → ATP → NAD⁺
B) glucose → NADH → electron transport chain → oxygen
C) glucose → pyruvate → acetyl CoA → ATP → oxygen
D) glucose → glycolysis → electron transport chain → NADH → ATP
E) glucose → glycolysis → citric acid cycle → NADH → ATP