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: Radiology
[{'content': 'Drug used to perform stress ECHO – \nSelect and explain. \nA. Thallium, B. Dobutamine, C. Adrenaline, D. Adenosine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Stress echocardiography is done either by Physical stress (Exercise :- treadmill or cycling) or by pharmacological stress (dobutamine).', 'role': 'assistant'}]