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: Dental
[{'content': 'Which sampling method is used in assessing immunization status of children under an immunization program \nSelect and explain. \nA. Quota sampling, B. Multistage sampling, C. Stratified random sampling, D. Cluster samping', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]