Sort the Following Molecules to Reflect the Order in Which

Short Answer

Sort the following molecules to reflect the order in which they carry electrons in the respiratory chain. Your answer would be a seven-letter string composed of letters A to G only, e.g. GFADCBE.
(A) NADH dehydrogenase complex
(B) Cytochrome c oxidase complex
(C) Cytochrome c reductase complex
(D) Cytochrome c
(E) Ubiquinone
(F) NADH
(G) H?O