Which Statement Concerning Coenzymes and Redox Reactions Is Incorrect

Which statement concerning coenzymes and redox reactions is incorrect?

A) Oxidation can be considered as loss of hydrogen or gain of oxygen.
B) Reduction can be considered as gain of hydrogen or loss of oxygen.
C) NAD⁺ is the oxidized form of NADH.
D) An oxidation reaction cannot occur unless a reduction reaction also occurs.
E) FAD is the reduced form of FADH₂.