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': 'Headache with bitemporal hemianopia with 6/6 vision seen with: \nSelect and explain. \nA. Optic neuritis, B. Trauma, C. Chiasmal lesions, D. B/L cavernous lesions', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Chiasmal lesions', 'role': 'assistant'}]