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: Medicine
[{'content': 'A 40-year-old lady with temporal field defects and galactorrhoea is most likely to have - \nSelect and explain. \nA. Pituitary macroadenoma, B. Craniopharyngioma, C. Lactational failure, D. Pregnancy', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Temporal field defects in women with galactorrhoea suggests pituitary macroadenoma.\nIncreased secretion of prolactin causes amenorrhoea, galactorrhoea and the mass effect of the tumour on the optic nerve produces headache and visual field defect.', 'role': 'assistant'}]