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: Unknown
[{'content': 'In patients who present with a penetrating chest injury, injury to the heart is most likely when the following physical sign(s) is/are present: \nSelect and explain. \nA. Hypotension, B. Distended neck veins., C. Decreased heart sound., D. Decreased venous pressure', 'role': 'user'}, {'content': "Answer: D \nExplanation: Hypotension, increased venous pressure (distended neck veins), and decreased heart sounds make up the classic Beck's triad associated with cardiac tamponade. If these three findings are present in a person who has a penetrating chest wound, intracardiac injury is almost certain and operative intervention is mandatory.", 'role': 'assistant'}]