This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Glaucoma, Subject name: Ophthalmology
[{'content': 'The normal cup disc ratio is - \nSelect and explain. \nA. 0.3, B. 0.6, C. 1.2, D. 2.4', 'role': 'user'}, {'content': 'Answer: A \nExplanation: \x01 Cup-disc ratio. Normal cup disc ratio is 0.3. (i) Large cup may be physiological or glaucomatous. (ii) Cup becomes full in papilloedema and papillitis. Ref.AK Khurana 4th edition page no 477', 'role': 'assistant'}]