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': 'Which one of the following is a good index of the severity of an acute disease? \nSelect and explain. \nA. Case fatality rate, B. Cause specific death rate, C. Standardized mortality ratio, D. Five year survival', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Case fatality rate measures the killing power of a disease, for acute infectious diseases like food poisoning, cholera, measles.\nIt is simply the\xa0ratio (it is not \xa0a RATE)\xa0of deaths to cases.', 'role': 'assistant'}]