This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Epidemiology, Subject name: Social & Preventive Medicine
True about case control study 
Select and explain. 
A. Less expensive, B. Those with disease and no diseased compared, C. Attributable risk is estimated, D. None of these
A: Less expensive
Answer: A: Less expensive 
Explanation: Advantages of case-control study: Easy to carry out Rapid and inexpensive Suitable to investigate rare disease Require comparatively few subjects Risk factors can be identified No attrition problems Ethical problems minimal (pg no: 74 park 23 rd edition)