<prompt> The most suitable measure for assessing the etiological role of a factor in a disease isRelative riskCase fatality rateAttributable riskPopulation attributable risk  <response>: The relative risk RR or risk ratio is the ratio of the probability of an outcome in an exposed group to the probability of an outcome in an unexposed group. Its a direct measure of the association between suspected cause and effect. Ref: 25th edition, Parks Textbook of Preventive and Social Medicine, Page no. 86 