This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Social & Preventive Medicine
[{'content': 'Prevalence is calculated by formula(2018) \nSelect and explain. \nA. Incidence x Mean durationx100, B. Incidence/ Mean duration x 100, C. Incidence/Mean duration, D. Incidence x Mean duration', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Relationship between prevalence and incidence Prevalence depends upon 2 factors, the incidence and duration of illness. Given the assumption that the population is stable, and incidence and duration are unchanging, the relationship between incidence and prevalence can be expressed as : P= IxD = incidence x mean duration Ref:- park; pg num:- 69', 'role': 'assistant'}]