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
True about Optic disc – a) Horizontal diameter 1.76 minb) Vertical diameter 1.88 mmc) Contain 1 million nerve fibred) Central retinal artery directly supplies this area 
Select and explain. 
A. ab, B. bc, C. abc, D. bcd
C: abc
Answer: C: abc 
Explanation: None