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': 'Field defect seen in pituitary adenoma is - \nSelect and explain. \nA. Bitemporal hemianopia, B. Binasal hemianopia, C. Quadrantanopia, D. "Pie in sky" defect', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The characteristic visual field defect in pituitary adenoma is bitemporal hemianopia due to central optic chiasma lesion. However in early stages qudrantanopia (superior: - Pie in sky or inferior: Pie on the floor) may also occur, but these are not characteristics.', 'role': 'assistant'}]