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': 'Most common cause of mortality in blunt thoracic trauma is: \nSelect and explain. \nA. Tension pneumothorax, B. Tracheo-bronchial injury, C. Hemothorax, D. Flail chest', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most common cause of mortality:-\n\nIn blunt thoracic trauma: Tracheobronchial injury.\nIn penetrating throracic trauma: Hemothorax.', 'role': 'assistant'}]