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': 'Fundoscopy of a patient shows chalky white optic disc with well defined margins. Retinal vessels and surrounding retina appears normal. Which of the following is the most likely diagnosis: \nSelect and explain. \nA. Primary Optic Atrophy, B. Post-neuritic secondary optic atrophy, C. Glaucomatous optic atrophy, D. Consecutive optic atrophy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Primary Optic Atrophy', 'role': 'assistant'}]