Please write an essay in which you first clearly identify a single major achievement in Epidemiology (e.g. Smallpox HIV/AIDS Tobacco Use Cholera). Then briefly describe one important tool that is used to measure its occurrence in a population. Briefly identify one source of public health data on that issue. Finally incorporating the concepts of risk and rates briefly discuss at least one major factor that influenced its occurrence.InstructionsYou can submit your paper in Question and Answer format. In other words list the questions and provide a short answer to each.