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: Medicine
[{'content': 'True statement regarding cardiac tamponatea) Kussumal sign positiveb) Enlargement of the cardiac silhouettec) Promenent y descentd) Electrical alternanse) Muffled heart sounds \nSelect and explain. \nA. abc, B. ade, C. ace, D. bde', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]