Answer:
The correct answer will be option-D.
Explanation:
During the electron transport chain, an electrochemical gradient is established due to the movement of electrons.
The high number of protons gets accumulated in the intermembrane space of the mitochondria whereas less number of protons present in the matrix.
The protons are pushed from the outer membrane to matrix through ATP synthase where the movement of ATP causes synthase to spin and bind ADP and Pi to produce ATP.
Thus, option-D is the correct answer.
