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
Regarding CRAo which is true? 
Select and explain. 
A. 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
A: Atherosclerosis in carotid aeries & emboli originating in hea are 2 most common cause
Answer: A: Atherosclerosis in carotid aeries & emboli originating in hea are 2 most common cause 
Explanation: A;Atherosclerosis in carotid aeries & emboli originating in hea are 2 most common cause