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': 'Amaurosis fugax does not occur in \nSelect and explain. \nA. Papillitis, B. Migraine, C. Giant cell arteritis, D. Venous stasis retinopathy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Amaurosis fugax is due to transient failure of retinal circulation.\nOccurs in papilledema but not in papillitis.', 'role': 'assistant'}]