This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
[{'content': 'Which of the following enzymes require NAD as cofactor? \nSelect and explain. \nA. Citrate Synthase, B. Isocitrate Dehydrogenase, C. a-Ketoglutarate dehydrogenase, D. Succinate Thiokinase', 'role': 'user'}, {'content': 'Answer: C \nExplanation: a-Ketoglutarate dehydrogenase REF: Harper 27th ed p. 496 NAD is cofactor in: Lactate dehydrogenase Pyruvate dehydrogenase Alpha ketoglutrate dehydrogenase', 'role': 'assistant'}]