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
Cerebral blood flow in an asphyxiated child is best measured by – 
Select and explain. 
A. NIRS, B. PET, C. Radionuclide imaging, D. MRI angiography
A: NIRS
Answer: A: NIRS 
Explanation: None