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': 'Extradural hematoma CT scan finding is \nSelect and explain. \nA. Hypodense biconvex lesion, B. Hyperdense biconvex lesion, C. Concavo convex hyperdense lesion, D. Low attenuated biconvex lesion', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Hyperdense biconvex lesion', 'role': 'assistant'}]