The following are the steps of chemiosmotic ATP synthesis in the light reaction. Arrange them in the correct order of their occurrence:
(A) H+ diffuses through ATP synthase and it makes ATP.
(B) Electrons from PS-II pass along the electron transport chain.
(C) H+ concentration gradient generates across the membrane.
(D) Light excites electrons in PS-II.

Correct option is B

· Step 1: Light excites electrons in Photosystem II (PS-II), leading to the release of high-energy electrons.
· Step 2: These electrons move along the electron transport chain (ETC), releasing energy.
· Step 3: This energy is used to pump H+ ions across the thylakoid membrane, creating a proton gradient.
· Step 4: H+ ions diffuse back through ATP synthase, which facilitates ATP synthesis from ADP and inorganic phosphate (Pi).