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: Surgery
[{'content': 'Which of the following is an absolute indication for surgery in cases of benign prostatic hyperplasia? \nSelect and explain. \nA. Nocturnal frequency, B. Bilateral hydroureteronephrosis, C. Recurrent urinary tract infection, D. Voiding bladder pressures > 50 cm of water', 'role': 'user'}, {'content': "Answer: B \nExplanation: Bilateral hydroureteronephrosis is an absolute indication for surgery in cases of benign prostatic hyperplasia. Ref: Bailey and Love's Sho Practice of Surgery, 24th Edition, Page 1376.", 'role': 'assistant'}]