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': 'The following is true about prevalence and incidence - \nSelect and explain. \nA. Both are rates, B. Prevalence is a rate but incidence is not, C. Incidence is a rate but prevalence is not, D. Both are not rates', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Incidence\nIncidence\xa0=\xa0No of new cases during a given time period\xa0/\xa0Population at risk during that period\xa0x 100\n\nNumerator (new cases) is a part of denominator (population at risk including those who have developed disease, i.e. the cases).\nTime period is specified\nMultiplier is 1000\n\n\nAll are features of rate, so incidence is a rate.\n\nPrevalence → Prevalence is proportion.', 'role': 'assistant'}]