This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Concept of health and disease, Subject name: Social & Preventive Medicine
[{'content': 'Who surveillance is done for all except \nSelect and explain. \nA. Polio, B. Viral encephalitis, C. Malaria, D. Relapsing fever', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ref:Park's Textbook of Community Medicine 25th Ed", 'role': 'assistant'}]