This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biostatistics, Subject name: Social & Preventive Medicine
All of the following are true about cluster sampling except- 
Select and explain. 
A. Samples are similar to those in simple Random sampling, B. Is a Rapid and simple method, C. The sample size may very according to study design, D. It is a type of probability sample
A: Samples are similar to those in simple Random sampling
Answer: A: Samples are similar to those in simple Random sampling 
Explanation: .