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
In the ninth revision of the international classification of diseases, 'Visual impairment' is a visual acuity in the better eye of: 
Select and explain. 
A. 18-Jun, B. Jun-36, C. Jun-60, D. Mar-60
C: Jun-60
Answer: C: Jun-60 
Explanation: Ans. 6/60