Which of the Following Events at the Electron-Transport Chain Occurs

Multiple Choice

Which of the following events at the electron-transport chain occurs last?

A) Hydrogen ions diffuse into inner mitochondrial compartment.
B) Hydrogen ions are moved from inner to outer mitochondrial compartment.
C) The movement of hydrogen ions through special channels is coupled to ATP production.
D) A hydrogen ion concentration gradient is established.
E) NADH transfer electrons to the electron-transport chain.