This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Screening, Subject name: Social & Preventive Medicine
Which is most economical and best screening 
Select and explain. 
A. Mass screening, B. High risk screening, C. Multiphasis screening, D. Any of the above
B: High risk screening
Answer: B: High risk screening 
Explanation: Ref:Parks 23rd edition pg 137 High-risk or selective screening : Screening will be most productive if applied selectively to high-risk groups, the groups defined on the basis of epidemiological research. Types of screening : Mass screening. High-risk or selective screening. Multi-phasic screening.