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: Social & Preventive Medicine
[{'content': 'Calculate the prevalence if incidence is 2 cases per 1000 population per year and mean duration is 4 years - \nSelect and explain. \nA. 8 Cases per 1000 population, B. 2 Cases per 1000 population, C. 0.5 Cases per 1000 population, D. 32 Cases per 1000 population', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., 8 Cases per 100 population o Prevalence = 2 x 4 = 8 Causes per 1000 populations", 'role': 'assistant'}]