The chemiosmotic coupling hypothesis of oxidative phosphorylation proposes that adenosine triphosphate (ATP) is formed because
A. A proton gradient forms across the inner membrane
B. There is a change in the permeability of the inner mitochondrial membrane towards adenosine diphosphate (ADP)
C. High-energy bonds are formed in mitochondrial proteins
D. ADP is pumped out of the matrix into the intermembrane space