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': 'Urinary catheterisation indicated in case of acute retention of urine in following conditions : \nSelect and explain. \nA. Stricture, B. Rupture, C. Postoperative, D. All', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e. Postoperative Trauma to urethra is an absolute contraindication to urethral catheterization. Stricture and acute prostatitis are relative contraindications. Catheterization is done preoperatively in some surgical procedures such as cardiac surgery, aoic or renal vascular surgery, craniotomy or major abdominal surgery or procedures in which large fluid shifts are expected. But not done for appendicectomy.", 'role': 'assistant'}]