This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuro-ophthalmology, Subject name: Ophthalmology
Down-beat nystagmus is seen in lesion of - 
Select and explain. 
A. Brainstem, B. Cerebellum, C. Basal ganglia, D. Hippocampus
B: Cerebellum
Answer: B: Cerebellum 
Explanation: Ref khurana 6/e p250