This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
[{'content': 'Random sampling is not done in? \nSelect and explain. \nA. Cluster sampling, B. Quota sampling, C. Stratified sampling, D. Simple random', 'role': 'user'}, {'content': "Answer: B \nExplanation: Quota sampling is a method for selecting survey paicipants that is a non-probabilistic version of stratified sampling. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 913", 'role': 'assistant'}]