Which of the following statements about NAD⁺ is true?

• A. NAD⁺ is reduced to NADH during glycolysis, pyruvate oxidation, and the Krebs cycle.
• B. NAD⁺ has more chemical energy than NADH.
• C. NAD⁺ donates high energy electrons to the electron transport chain.
• D. In the absence of NAD+, glycolysis can still function.