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 MCH programme the sampling is done by which method- \nSelect and explain. \nA. Systemic, B. Stratified, C. Group, D. Cluster-30', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Cluster-30", 'role': 'assistant'}]