19. A three-month-old baby is diagnosed with pyruvate dehydrogenase complex deficiency. Which of the following coenzyme is NOT required by this enzyme complex to convert pyruvate to acetyl-CoA? (A) Thiamine pyrophosphate (B) Nicotinamide adenine dinucleotide (C) Lipoamide (D) Flavin adenine dinucleotide (E) None of the above