Which of the Following Is Correct with Respect to the Redox

Which of the following is correct with respect to the redox pair NAD⁺/NADH?

A) The nicotinamide ring is a relatively stable aromatic structure.
B) The nicotinamide ring is a heteroaromatic because it has a noncarbon atom in position 4.
C) The nicotinamide ring may accept two electrons at carbon 1, becoming a nonaromatic ring.
D) The reduced, nonaromatic ring of NADH is at a higher energy than the aromatic ring of NAD⁺.
E) All of the above are correct.