Indicate whether each of the following descriptions better applies to cytochrome c oxidase complex (O), cytochrome c reductase complex (R), or NADH dehydrogenase complex (N). Your answer would be a four-letter string composed of letters O, R, and N only, e.g. RONN.
( ) It is the largest of the three respiratory complexes.
( ) It accounts for the majority of O? uptake in most cells.
( ) It employs the Q cycle to increase proton pumping.
( ) It contains separate modules for electron transport and proton pumping.