The Reduced Coenzymes NADH and FADH2 Provide Hydrogen Ions and Electrons

Multiple Choice

The reduced coenzymes NADH and FADH2 provide hydrogen ions and electrons for the following reaction: 4H⁺ + 4e⁻ + O₂ → 2H₂O. Which of the following statements is true of this reaction?

A) It is an endothermic reaction wherein two electrons are consumed.
B) It is an exothermic reaction wherein two electrons are consumed.
C) It is an endothermic reaction wherein four electrons are consumed.
D) It is an exothermic reaction wherein four electrons are consumed.