A Politician Asks an Epidemiologist How Many Cases of Coronary

A politician asks an epidemiologist how many cases of coronary heart disease can be prevented if they manage to eliminate the exposure to smoking in city A.The epidemiologists explain that,if they eliminate smoking,they could prevent 22% cases of coronary heart disease.What measure of association was used to answer this question?

A) Population attributable risk
B) Odds ratio
C) Relative risk
D) Incidence rate
E) Risk ratio