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': 'Cardiotoxicity caused by radiotherapy and chemotherapy is best detected by: \nSelect and explain. \nA. Echocardiography, B. Endomyocardial biopsy, C. ECG, D. Radionuclide scan', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. Endomyocardial biopsy', 'role': 'assistant'}]