<prompt> In ETC, Oxidative phosphylaion ATP formation is regulated by:NADH Co-Q reductaseCytochrome C oxidaseCo-Q-Cytochrome C reductasevAll of the abobe  <response>: A, B, C i.e. NADH Co-Q reductase, Cytochrome C oxidase, Co-Q-Cytochrome C reductase Mitchells chemiosmotic hypothesis links the respiratory i.e. electron transpo chain to ATP production i.e. oxidative phosphorylationQ. It explains how the free energy generated by the transpo of electrons from NADH to molecular oxygen in respiratory chain is used to produce ATP from ADP Fi from proton pumps. For each NADH oxidized pair of electron, complex I NADH -Q- oxido reductase and complex III ubiquinone Qcytochrome C- oxidoreductase pump translocate 4 protons H each, whereas complex IV Cytochrome C- oxidase translocates only 2 protons H. In ETC. oxidative phosphorylation ATP formation occurs at these sites ie complex I, III IV 