Which of the Following Is TRUE Regarding the Complexes Within

Which of the following is TRUE regarding the complexes within the electron transport system?
(I) Complex II contributes twice as many protons to the gradient than Complex I
(II) Inhibition of Complex II would decrease the total number of electrons moving through the electron transport chain.
(III) Inhibition of Complex II would not alter the amount of free energy generated from electrons originating from NADH.
(IV) Complex I can accept electrons with higher potential than Complex II is able to accept.

A) I,II,III,IV
B) I,II,III
C) II only
D) II,III
E) III,IV