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 are true about cluster sampling except? 
Select and explain. 
A. Sample size is same as that of simple random sampling, B. It is a two stage sampling, C. It is cheapter than other methods of sampling, D. It has a disadvantage of higher sampling error
A: Sample size is same as that of simple random sampling
Answer: A: Sample size is same as that of simple random sampling 
Explanation: .