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': 'Visual axis is – \nSelect and explain. \nA. Center of cornea to retina, B. Object to fovea, C. Center of lens to cornea, D. None', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Optical axis:- Axis passing through centres of the cornea, lens to the retina.\nVisual axis:- Line passing through fixation point (object) to the fovea.', 'role': 'assistant'}]