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': 'National immunization programme, all are involved except – \nSelect and explain. \nA. TT, B. Hepatitis B, C. OPV, D. Measles', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]