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
Most common adverse effect of oral contraceptive is: 
Select and explain. 
A. Colour blindness, B. Optic neuritis, C. Ringscotoma, D. Nystagmus
B: Optic neuritis
Answer: B: Optic neuritis 
Explanation: Ans. Opticneuritis