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: Unknown
The odds ratio is designated as - 
Select and explain. 
A. ab/cd, B. ac/bd, C. bd/ac, D. ad/bc
D: ad/bc
Answer: D: ad/bc 
Explanation: Ans. is 'd' i.e., ad/bc Odds - ratio (cross product ratio)o From a case-control study odds ratio can be derived which a measure of the strength of association between risk factor and outcome.o The odds ratio is closely related to relative risk (which is analyzed in a cohort study) - odds ratio represents only an estimate of relative risk.o The odds ratio is the cross product of entries in above tableOdds ratio =adbeo The odds ratio is a key parameter in the analysis of case-control studies.