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': "Which of the following is not a feature of cardiac tamponade? \nSelect and explain. \nA. Pulsus paradoxus, B. Kussmaul's sign, C. Electrical Alternans, D. Diastolic collapse of right ventricle on echocardiogram", 'role': 'user'}, {'content': "Answer: B \nExplanation: Kussmaul's sign", 'role': 'assistant'}]