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
[{'content': 'In retinitis pigmentosa, following are true except – \nSelect and explain. \nA. Pigments present, B. Pale waxy disc, C. Narrowing of vessels, D. ERG – normal', 'role': 'user'}, {'content': 'Answer: D \nExplanation: ERG is markedly subnormal in retinitis pigmentosa.\nThere is perivascular pigment deposition, pale- waxy disc and marked attenuation (narrowing) of retinal vessels', 'role': 'assistant'}]