This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Communicable diseases, Subject name: Social & Preventive Medicine
[{'content': 'After vaccination againts Japanese encephalitis immunity developes in - \nSelect and explain. \nA. 30 days, B. 7 days, C. 10 days, D. 21 days', 'role': 'user'}, {'content': "Answer: A \nExplanation: Protective immunity develops in about one month time after the second dose.Ref.PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 21st edition page no 261", 'role': 'assistant'}]