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: Ophthalmology
[{'content': 'According to WHO, blindness is defined as: September 2009, 2010 \nSelect and explain. \nA. Visual acuity of less than 1/60, B. Visual acuity of less than 3/60, C. Visual acuity of less than 6/60, D. Visual acuity of less than 6/18', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: Visual acuity of less than 3/60 As per WHO, blindness is defined as Visual acuity of less than 3/60 in the better eye with befit possible correction.', 'role': 'assistant'}]