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
Blindness as defined by WHO is the visual acuity of less than 
Select and explain. 
A. 18-Jun, B. 24-Jun, C. Jun-60, D. Mar-60
D: Mar-60
Answer: D: Mar-60 
Explanation: WHO has defined blindness as "visual acuity of less than 3/60 (Snellen) or its equivalent".