This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
[{'content': 'Blindness as defined by WHO is the visual acuity of less than \nSelect and explain. \nA. 18-Jun, B. 24-Jun, C. Jun-60, D. Mar-60', 'role': 'user'}, {'content': 'Answer: D \nExplanation: WHO has defined blindness as "visual acuity of less than 3/60 (Snellen) or its equivalent".', 'role': 'assistant'}]