What happens at the end of the chain in Figure 7.2?
A) Two electrons combine with a molecule of oxygen and two hydrogen atoms.
B) Two electrons combine with a proton and a molecule of NAD+.
C) Four electrons combine with a molecule of oxygen and 4 protons.
D) Four electrons combine with four hydrogen and two oxygen atoms.
E) One electron combines with a molecule of oxygen and a hydrogen atom.
Answer: C