Fact 1: Electron transport is the final stage of aerobic respiration. Fact 2: Aerobic respiration is an oxidative process which uses oxygen as a final electron acceptor. Given the two facts above, what is oxygen used as in respiration?

(a). heat produced;
(b). electron acceptor;
(c). photosynthesis;
(d). Chemical energy;
(e). preventing heat transfer;
(f). Veins and arteries.;
(g). it keeps an organism warm;
(h). It helps them survive;
The answer is:
(b).