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
Retinitis pigmentosa is a feature of all except – 
Select and explain. 
A. Refsum's disease, B. Hallervorden–Spatz disease, C. NARP, D. Abetalipoproteinemia
B: Hallervorden–Spatz disease
Answer: B: Hallervorden–Spatz disease 
Explanation: None