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': 'All of the following holds true about cluster sampling, except: \nSelect and explain. \nA. Is a Rapid and simple method, B. Samples are similar to those in Simple Random Sampling, C. It is a type of probability sample, D. The sample size may vary according to study design', 'role': 'user'}, {'content': "Answer: B \nExplanation: Cluster sampling is entirely different from Random sampling. The following are differences between random sampling and cluster sampling. Ref: Park's Texbook of Preventive and Social Medicine 19th Edition; Pages 702; High Yield Biostatistics by Anthony N. Glaser 2nd Edition, Pages 2 -3; Methods in Biostatistics By Mahajan6th Edition, Pages 96 - 100; Sampling of Populations: Methods and Applications By Paul S. Levy, Stanley Lemeshow 4th Edition; Pages 269 - 272; 223 - 229.", 'role': 'assistant'}]