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': 'Cerebral blood flow in an asphyxiated child is best measured by – \nSelect and explain. \nA. NIRS, B. PET, C. Radionuclide imaging, D. MRI angiography', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]