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': 'Which radionuclide is most commonly used for Infarct scanning \nSelect and explain. \nA. Tc-99m pyrophosphate, B. Tc-99m Sestamibi, C. Tc-99m Sulfur Colloid, D. Tc-99m Red blood cells', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tc-99m pyrophosphate is used most commonly.\nInfarct appears as Hotspot.', 'role': 'assistant'}]