According to chemiosmotic hypothesis, ATP synthase produce ATP when protons (H⁺):

• A

  Move from stroma to thylakoid lumen by simple diffusion

• B

  Move from stroma to thylakoid lumen by facilitated diffusion

• C

  Move from thylakoid lumen to stroma by active transport

• D

  Move from thylakoid lumen to stroma by facilitated diffusion