What is adenosine triphosphate made of ?

Assertion A: During photophosphorylation protons are transported across the membrane and accumulated inside the lumen.

Reason R: To develop proton gradient, pheophytin transfers electrons to hydrogen carriers instead of electron carrier.

Which of the following are required for chemiosmosis?

I. A membrane

I. A neutron pump

II. An electron gradient

IV. $\mathrm{ATPase}$

The correct answer is:

Identify the parts marked as $\mathrm{A}\mathrm{ },\mathrm{ }\mathrm{B}$ and $\mathrm{C}$ in the given figure showing ATP synthesis through chemiosmosis.

** Options were incomplete and changes were made accordingly.