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
[{'content': 'Ratio of incidence of a disease among the exposed to the incidence among non-exposed is: \nSelect and explain. \nA. Odds ratio, B. Relative risk, C. Absolute risk, D. Attributable risk', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref. Foundations of Community medicine. Page. 596\n\xa0\nMeasures of effect\n\nMeasures of effect are used in epidemiological studies to assess the strength of an association between a putative risk factor and the subsequent occurrence of disease.\nThis requires that the incidence of disease in a group of persons exposed to a potential risk factor is compared with the incidence in a group of persons not exposed to the potential risk factor.\nThis comparison can be summarized by calculating either the ratio of measures of disease frequency for the two groups or the difference between the two, and reflects the increase in frequency of disease in one population compared with another, treated as baseline.\n\n\xa0\nThree main measures of effect', 'role': 'assistant'}]