This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Neuro-ophthalmology, Subject name: Ophthalmology
[{'content': 'Field defect seen in pituitary adenoma- \nSelect and explain. \nA. Bitemporal hemianopia, B. Binasal hemianopia, C. Quadrantanopia, D. "Pie in sky" defect', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Bitemporal hemianopia. Sagittal (central) lesions of the chiasma. These are characterised by bitemporal hemianopia and bitemporal hemianopic paralysis of pupillary reflexes. These usually lead to paial descending optic atrophy. Common causes of central chiasmal lesion are: suprasellar aneurysms, tumours of pituitary gland, craniopharyngioma, suprasellar meningioma and glioma of third ventricle, third ventricular dilatation due to obstructive hydrocephalus and chronic chiasmal arachnoiditis. Ref :AK Khurana 4thE pg 290', 'role': 'assistant'}]