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: Radiology
[{'content': 'All of the following calcify except – \nSelect and explain. \nA. Medulloblastoma, B. Sturge weber syndrome, C. Meningioma, D. Ependymoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Calcification is very rare in medulloblastoma.', 'role': 'assistant'}]