Correct option (c) Chemiosmotic Theory
Explanation:
As per Peter Mitchell'* chemiosmotic- coupling hypothesis, outward pumping of protons across the inner chloroplast or mitochondrial membrane results in accumulation of protons between outer membrane and inner membrane. A proton gradient is thus established. As protons now flow back, passively down the gradient, the proton motive force is utilised to synthesise ATP.
