This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
In case control study, the risk is calculated by? 
Select and explain. 
A. Relative risk, B. Attributable risk, C. Cross product ratio, D. None
C: Cross product ratio
Answer: C: Cross product ratio 
Explanation: Ans. is 'c' i.e., Cross product ratio o Risk in case control study is calculated by odds ratio (cross product ratio).