16. You are breathing in oxygen and breathing out carbon dioxide. Most of the carbon dioxide arises from(A) glucose in glycolysis.(B) NAD⁺ redox reactions in the mitochondrial matrix(C) NADH redox reactions on the inner mitochondrial membrane.(D) FADH₂ in the electron transfer system.(E) the oxidation of pyruvate, isocitrate, and α-ketoglutarate in the citric acid cycle.