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
In retinitis pigmentosa, following are true except – 
Select and explain. 
A. Pigments present, B. Pale waxy disc, C. Narrowing of vessels, D. ERG – normal
D: ERG – normal
Answer: D: ERG – normal 
Explanation: ERG is markedly subnormal in retinitis pigmentosa.
There is perivascular pigment deposition, pale- waxy disc and marked attenuation (narrowing) of retinal vessels