This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney, Subject name: Pharmacology
Long-term use of which diuretic agent can result in gynaecomastia? 
Select and explain. 
A. Amiloride, B. Spironolactone, C. Triamterene, D. Acetazolamide
B: Spironolactone
Answer: B: Spironolactone 
Explanation: Side effects of spironolactone: - Drowsiness, Ataxia, Mental confusion, Epigastric distress It may enhance testosterone clearance or its peripheral conversion to estradiol- gynecomastia, erectile dysfunction or loss of libido in men, and breast tenderness or menstrual irregularities in women. Most serious is hyperkalemia that may occur, especially if renal function is inadequate.