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
Simple random sampling- 
Select and explain. 
A. Provides least number of possible samples, B. Haphazard collection of ceain number for a sample, C. Picking every 5th or 10th at regular intervals, D. Sample represent, a corresponding strata of universe
B: Haphazard collection of ceain number for a sample
Answer: B: Haphazard collection of ceain number for a sample 
Explanation: .