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': 'The most common fieid defect in papillitis is: \nSelect and explain. \nA. A relative central or centrocaecal scotoma, B. Enlargement of the blind spot, C. Tubular vision, D. Multiple small peripheral scotomas', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A relative central or centrocaecal scotoma', 'role': 'assistant'}]