This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Ophthalmology
[{'content': 'All are true regarding optic neuritis except: \nSelect and explain. \nA. Decreased visual acuity, B. Decreased pupillary reflex, C. Abnormal electroretinogram, D. Abnormal visual evoked response retinogram', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Electroretinogram indicates the activity of retinal (esp. rods & cones) function and has no role in assessing the functional integrity of the optic nerve. So it can&;t be abnormal in optic neuritis. Ref: AK khurana 7th ed.', 'role': 'assistant'}]