Analyze the sequence of electron flow through the four main protein complexes in the electron transport chain.

• A. Cytochrome c oxidase, cytochrome bc1, succinate dehydrogenase, NADH dehydrogenase.
• B. NADH dehydrogenase, succinate dehydrogenase, cytochrome bc1, cytochrome c oxidase.
• C. Cytochrome bc1, NADH dehydrogenase, cytochrome c oxidase, succinate dehydrogenase.
• D. Succinate dehydrogenase, NADH dehydrogenase, cytochrome c oxidase, cytochrome bc1.

Answer: (B)