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
[{'content': 'During an epidemiological investigation, which of the following steps would most likely follow comparison of the hypothesis with the established facts? \nSelect and explain. \nA. Determination of who is at risk of having the health problem, B. Confirmation of the diagnosis, C. Estimation of the number of cases, D. Proposal of measures for control and prevention', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Proposing measures of control and prevention should only take place after the investigation has defined the cause and determined the distribution of the population at risk. Although the exact sequence may vary, the ultimate purpose of an epidemiological investigation is to control a health problem in a community.', 'role': 'assistant'}]