This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Sampling, Subject name: Social & Preventive Medicine
Which of the following is example of Non-random sampling 
Select and explain. 
A. Probability sampling, B. Non-purposive sampling, C. Cluster random sampling, D. Clinical trial sampling
D: Clinical trial sampling
Answer: D: Clinical trial sampling 
Explanation: Examples of Non-random (Non-probability sampling/ Purposive sampling) sampling: Convenience sampling Quota sampling Snow ball sampling Clinical trial sampling