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': 'Which positive test does not necessarily indicate HIV infection in a newborn ? \nSelect and explain. \nA. ELISA for HIV IgG antibody, B. p24 antigen, C. Virus culture, D. ELISA for HIV IgA antibody', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]