This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Surgery
Opsomyoclonus is encountered as C/F of 
Select and explain. 
A. Meningioma, B. Cerebral atrophy, C. Excision, D. Neurofibramatosis
B: Cerebral atrophy
Answer: B: Cerebral atrophy 
Explanation: At least 50% of children with opsoclonus-myoclonus have an underlying neuroblastoma." - Harrison Opsoclonus-Myoclonus Syndrome Opsoclonus is a disorder of eye movement characterized by involuntary, chaotic saccades that occur in all directions of gaze; it is frequently associated with myoclonus and ataxia. Causes of Opsoclonus-myoclonus Idiopathic Cancer-related (paraneoplastic) Cancers associated with opsoclonus-myoclonus are usually lung and breast cancers in adults and neuroblastoma in children. Ref : Harrison 17/e p626