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': 'Lesion in the optic chiasma causes -a) Bitemporal hemianopiab) Upper nasalc) Lower nasald) Upper temporale) Lower temporal \nSelect and explain. \nA. acd, B. bde, C. ade, D. ad', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Central lesions of optic chiasma\n\n\nCharacteristic visual field defect → Bitemporal hemianopia\n\n\nInitially temporal quadrantanopia may occur :-\n\n\nLesion compressing from below → upper temporal\nLesion compressing from above → lower temporal\n\nLateral lesions of optic chiasma → Binasal hemianopia', 'role': 'assistant'}]