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: Pathology
[{'content': "Lesion in Wernicke's encephalopathy occurs in - \nSelect and explain. \nA. Mamillary body, B. Cerebellum, C. Motor cortex, D. Substantia nigra", 'role': 'user'}, {'content': 'Answer: A \nExplanation: In thiamine deficiency, hemorrhages into the mamillary bodies cause Wernicke-korsakof syndrome.\nOther regions of CNS involved in thiamine deficiency are periventricular regions of the thalamus, the floor of the fourth ventricle and the anterior region of the cerebellum.', 'role': 'assistant'}]