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
A 30-year-old women pretests a history of amenorrhoea and impaired vision of six-month' duration. Physical examination shows everything except for pale optic discs and diminished visual acuity. The most likely diagnosis is - 
Select and explain. 
A. Craniopharyngioma, B. Pituitary adenoma, C. Hypothalamic glioma, D. Benign intracranial hypertension
B: Pituitary adenoma
Answer: B: Pituitary adenoma 
Explanation: pituitary adenoma inhibits GnRH causes an imbalance in FSH and LH causing amenorrhea and increased ICT causes compression of optic disc & visual field defects