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: Dental
[{'content': 'Which of the following is a better indicator of the severity of an acute disease: \nSelect and explain. \nA. Cause specific death rate., B. Case fatality rate., C. Standardized mortality ratio., D. Five year survival rate.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]