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: Surgery
[{'content': 'A 24-year old man falls on the ground when he is struck in the right temple by a baseball. While being driven to the hospital, he lapses into coma. He is unresponsive with the dilated right pupil when he reaches the emergency department. The most important step in initial management is : \nSelect and explain. \nA. Craniotomy, B. CT scan of the head, C. X-ray of the skull and cervical spine, D. Doppler ultrasound examination of the neck', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Coma with a dilated pupil after a lucid interval following a head injury must be assumed to represent an epidural hematoma.\nEmergency evacuation of the clot without time-consuming studies is vital to restore cerebral function. CT scan is done with a patient in less critical condition.', 'role': 'assistant'}]