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
Which radionuclide is most commonly used for Infarct scanning 
Select and explain. 
A. Tc-99m pyrophosphate, B. Tc-99m Sestamibi, C. Tc-99m Sulfur Colloid, D. Tc-99m Red blood cells
A: Tc-99m pyrophosphate
Answer: A: Tc-99m pyrophosphate 
Explanation: Tc-99m pyrophosphate is used most commonly.
Infarct appears as Hotspot.