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': 'Eradication of polio type 2 done on \nSelect and explain. \nA. 12-May-14, B. 20-Sep-15, C. 14-Jul-16, D. 22-Feb-03', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]