The correct option is C Cytochromes
Both respiration and photosynthesis involve electron transfer across a series of electron carriers embedded in the inner mitochondrial membrane and the thylakoid membranes respectively. Cytochromes are responsible for ATP production through electron transport and are iron-containing proteins. They catalyze redox reactions and the heme group interconverts between oxidation states Fe2+ (reduced) and Fe3+ (oxidized) states.