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': 'Minimum visual acuity below which a person is called Blind \nSelect and explain. \nA. Jan-60, B. Mar-60, C. Feb-60, D. Apr-60', 'role': 'user'}, {'content': 'Answer: B \nExplanation: According to WHO, minimum visual acuity below which a person is called Blind is 3/60.', 'role': 'assistant'}]