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: Medicine
[{'content': 'Antibiotic prophylaxis is not used for? \nSelect and explain. \nA. Child under 15 years, B. In renal failure patient, C. In liver failure patient, D. HIV patient', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]