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': 'Definition of measles elimination- \nSelect and explain. \nA. <1\\/1000, B. <1\\/10000, C. <1\\/100000, D. <1\\/100', 'role': 'user'}, {'content': "Answer: C \nExplanation: WHO define elimination of measles as the absence of endemic measles for a period of grater than 12 months in the presence of adequate surveillance measles incidence less than 1/100,000 population. REF. PARK'S TEXTBOOK OF PREVENTIVE AND SOCIAL MEDICINE 21ST EDITION. - 137", 'role': 'assistant'}]