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: Medicine
In which of the following conditions, neurons are exclusively affected - 
Select and explain. 
A. Spinocerebellar ataxia, B. Supranuclear palsy, C. Corticobasal degeneration, D. Multisystem Atrophy
A: Spinocerebellar ataxia
Answer: A: Spinocerebellar ataxia 
Explanation: None