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': 'In the WHO recommended EPI Cluster sampling for assessing primary immunization coverage, the age group of children to be surveyed is- \nSelect and explain. \nA. 0-12 months, B. 6-12 months, C. 9-12 months, D. 12-23 months', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]