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: ENT
Central mystagmus ? 
Select and explain. 
A. Suppressed by optic fixation, B. More than 1 minute duration, C. Fixed direction, D. Fatiguable
B: More than 1 minute duration
Answer: B: More than 1 minute duration 
Explanation: Ans. is `b' i.e., More than 1 minute duration