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': 'All of the following are true about medulloblastoma except? \nSelect and explain. \nA. It is the most common primary malignant brain tumor in childhood, B. Isochrome 17q indicates poor prognosis, C. Most common site is brainstem (medulla), D. Tumor is highly radio sensitive', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Medulloblastoma occurs exclusively in the cerebellum.', 'role': 'assistant'}]