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': 'Disability certificate is given for poor vision if visual acuity is 4/60, in tune of visual impairment as a percentage \nSelect and explain. \nA. 1, B. 0.75, C. 0.3, D. 0.4', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]