The Following Reaction Summarizes the Overall Chemical Change That Takes

The following reaction summarizes the overall chemical change that takes place as the result of electrons transferred along the respiratory chain. The formation of ATP from ADP and P_i requires the input of 7.3 kcal/mol.The respiratory chain can efficiently convert the majority of the free energy released from electrons to the chemical energy of phosphate bonds in ATP molecules, without a lot of wasted energy given off as heat.Which characteristic of the respiratory chain explains how this is possible?

A) The number of components in the respiratory chain
B) The sizes of the components of the respiratory chain
C) The protein nature of many of the components in the respiratory chain
D) The location of the components in the inner mitochondrial membrane
E) The identity of the final electron acceptor at the end of the respiratory chain