Which Statement Is NOT a Feature of Complex IV

Multiple Choice

Which statement is NOT a feature of Complex IV?

A) Cytochrome c is a one-electron donor.
B) Oxygen is a substrate.
C) Copper is an essential metal for the reaction.
D) For every electron passed to Complex IV, two protons are consumed from the matrix (N) side.
E) In order to generate two water molecules, Complex IV must go through the catalytic cycle two times.