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': 'Axial resolution in optical coherence tomography is about: \nSelect and explain. \nA. 10 m, B. 30 m, C. 100 m, D. 300 m', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. 10 m', 'role': 'assistant'}]