​When Hydrogen Ions Accumulate in the Mitochondrial Intermembrane Space, What

Multiple Choice

​When hydrogen ions accumulate in the mitochondrial intermembrane space, what prevents them from moving back into the mitochondrial matrix without flowing through ATP synthase?

A) ​The hydrophilic environment of the mitochondrial matrix repels hydrogen ions.
B) ​The hydrophobic environment of the mitochondrial matrix repels hydrogen ions.
C) ​Hydrogen ions combine with oxygen gas to form water, which cannot cross the lipid bilayer of the mitochondrial membrane.
D) ​Hydrogen ions cannot cross the lipid bilayer of the mitochondrial membrane.
E) ​Entering the matrix would require the ions to move against their concentration gradient.