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 60 year old man, with an accident and comes to emergency department with engorged neck veins, pallor, rapid pulse. He has muffled heart sounds. The likely diagnosis is \nSelect and explain. \nA. Cardiac tamponade, B. Aortic dissection, C. Pneumothorax, D. Diaphragmatic rupture', 'role': 'user'}, {'content': 'Answer: B \nExplanation: This is a case of cardiac tamponande.\nBecks traid - muffled heart sounds + engorged neck veins + decreased BP', 'role': 'assistant'}]