Which statement about the respiratory chain best explains the information presented in the graph? A. During electron transport along the respiratory chain, protons are actively transported across the inner mitochondrial membrane to create a proton gradient. B. Extensive folding of the inner mitochondrial membrane allows a larger number of protein components in the respiratory chain than would otherwise fit. C. The components of the respiratory chain are arranged in order so that an electron passing from one to the next undergoes a sequential drop in energy. D. The movement of protons from a high concentration in the intermembrane space to a low concentration in the mitochondrial matrix is coupled to the synthesis of ATP from ADP and Pi. E. The gradient of protons established across the inner mitochondrial membrane as a result of electron transport is a source of potential energy.