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': 'Extent of cardiotoxicity of chemotherapy and radiotherapy is best diagnosed by: \nSelect and explain. \nA. Echocardiogram, B. Radionuclide scan, C. ECG, D. Endomyocardial biopsy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Endomyocardial biopsy', 'role': 'assistant'}]