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': 'What is false about case fatality rate? \nSelect and explain. \nA. It is a ratio, B. It is not useful for acute disease, C. Related to virulence, D. Not useful in chronic diseases', 'role': 'user'}, {'content': "Answer: B \nExplanation: Case fatality rate represents the killing power of the disease. It's simply the ratio of deaths to diseases. Ref: 25th edition, Park's Textbook of Preventive and Social Medicine, Page no. 66", 'role': 'assistant'}]