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: Pediatrics
[{'content': 'What is the best method to diagnose HIV in an infants? \nSelect and explain. \nA. Western Blot, B. ELISA, C. PCR, D. All of the  above', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In children younger then 18 months of age, WHO recommended HIV DNA or RNA PCR to diagnose HIV infection, as maternal antibodies may interface with antibody detetion.\nIn children > 18 months of age, demonstration of IgG antibody of\xa0HIV by ELISA and western blot establishes HIV infection.', 'role': 'assistant'}]