Which product does the krebs cycle require from the electron transport chain?

NAD+ and FAD+

Explanation:

Kreb's cycle is process that breaks down acetyl CoA into carbon dioxide and water. It uses NAD+ and FAD+ as electron acceptors for its redox reactions. The NADH and FADH2 formed during Kreb's cycle enter electron transport chain to donate their electrons to oxygen and to get oxidized into NAD+ and FAD+ respectively. Without supply of NAD+ and FAD+ from electron transport chain, the redox reactions of Kreb's cycle cannot occur.

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c is the correct answer!