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': 'In an outbreak of cholera in a village of 2000 population 20 cases have occurred and 5 have died. Case fatality rate is ? \nSelect and explain. \nA. 1%, B. 0.25%, C. 5%, D. 25%', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is `d' i.e., 25%", 'role': 'assistant'}]