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: Social & Preventive Medicine
[{'content': 'As per immunisation schdule, Hepatitis A vaccine is recommended at: \nSelect and explain. \nA. 1 year, B. 2 years, C. 5 years, D. 10 years', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 2 years', 'role': 'assistant'}]