Answer:
The correct answer is the third statement.
Explanation:
ETS or electron transport chain is the last stage of aerobic cellular respiration that leads to the formation of a huge amount of adenosine triphosphate also known as ATP which is the energy currency of the cell.
It occurs in the inner mitochondrial membrane. Electrons are passed through various protein complexes present in the inner membrane of mitochondria.
As electrons pass through the electron transport chain, electrons move from a higher to a lower energy level and are ultimately passed to oxygen.
During this process, Energy release in the electron transport chain is trapped as a proton gradient. Due to this concentration gradient, ATP synthase is a final protein complex, forms ATP.
Thus, the correct answer is the third statement.