This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Non-Communicable Diseases, Subject name: Social & Preventive Medicine
[{'content': 'According to WHO. blindness is defined as a visual acuity of the better eye, less than - \nSelect and explain. \nA. Jun-60, B. May-60, C. Apr-60, D. Mar-60', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. is \'d\' i.e., 3/60 Blindnesso WHO has proposed a uniform criterion and defined blindness as "Visual acuity of less than 3/60 or its equivalento In the absence of appropriate vision charts, the WHO has now added the "inability to count fingers in daylight at a distance of 3 metres" Xo indicates less than 3/60 or its equivalent.', 'role': 'assistant'}]