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': 'Regarding CRAo which is true? \nSelect and explain. \nA. Atherosclerosis in carotid aeries & emboli originating in hea are 2 most common cause, B. Relative afferent pupillary defect is absent, C. Local intraaerial thrombolysis has proven benefit, D. Majority of patient will recover to gain good visual acuity', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A;Atherosclerosis in carotid aeries & emboli originating in hea are 2 most common cause', 'role': 'assistant'}]