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': 'Which one of the following is a good index of the serverity of an acute disease \nSelect and explain. \nA. Cause specific death rate, B. Case fatality rate, C. Standardized moality ratio, D. Five year survival', 'role': 'user'}, {'content': 'Answer: B \nExplanation: ref: Park&;s 23rd edition pg 58 Case fatality rate measures the killing power of a disease, for acute infectious diseases like food poisoning, cholera, measles. it is simply the ratio (it is not a RATE) of deaths to cases.', 'role': 'assistant'}]