This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: vitamins, Subject name: Biochemistry
[{'content': 'Which of the following vitamin deficiency causes Wernicke Korsakoff syndrome? \nSelect and explain. \nA. Thiamin, B. Riboflavin, C. Niacin, D. Cobalamin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Vitamin Functions Deficiency Disease B1 Coenzyme in pyruvate and a-ketoglutarate dehydrogenases, and transketolase Regulates Cl- channel in nerve conduction Peripheral nerve damage (beriberi) or central nervous system lesions (Wernicke Korsakoff syndrome) Reference: Harper; 30th edition; Page no: 550', 'role': 'assistant'}]