This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Retina, Subject name: Ophthalmology
[{'content': 'All of the following may be used to differentiate Central Retinal Venous Occlusion (CRVO) from Ocular Ischemic Syndrome due to Carotid Artery Stenosis, Except \nSelect and explain. \nA. Dilated retinal vein, B. Tortuous retinal vein, C. Retinal artery pressure, D. Ophthalmodynamometry', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) Dilated Retinal veinRef: Yanoff 3/e, p. 625Central Retinal vein occlusion and Ocular Ischemic Syndrome due to carotid artery stenosis are both associated with dilated Retinal veins and hence this feature cannot be used to distinguish these conditions.', 'role': 'assistant'}]