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
The ratio between incidence among exposed and nonexposed persons is called- 
Select and explain. 
A. Attributable risk, B. Positive predictive value, C. Relative risk, D. Odds ratio
C: Relative risk
Answer: C: Relative risk 
Explanation: .relative risk also called as risk ratio ,is the ratio of the incidence of the disease or death among exposed and incidence among non exposed.it is a direst measure of strength of association between suspected cause and effect.RR of one indicates no association,it must also be noted that risk does not necessarily imply causal association ref:park&;s textbook,ed22,pg no 75