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 toward adenosine diphosphate $(ADP)$
• C
  high energy bonds are formed in mitochondrial proteins
• D
  $ADP$ is pumped out of the matrix into the intermembrane space.