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': 'Which of the following is the classic CT appearance of an acute subdural hematoma – \nSelect and explain. \nA. Lentiform–shaped hyperdense lesion, B. Cresent–shaped hypodense lesion, C. Cresent–shaped hyperdense lesion, D. Lentiform–shaped hypodense lesion', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Subdural hematoma\n\n\nCresent (concavo-convex) shaped\nHyperdense (2/3) or mixed (1/3) in acute cases\nIsodense in subacute\nHypodense in chronic', 'role': 'assistant'}]