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': 'Following trauma, a patient presents with a drop of blood at the tip of urinary meatus. He complains of inability to pass urine. Next step should be: \nSelect and explain. \nA. IVP should be done, B. MCU should be done, C. Catheterise, drain bladder and remove the catheter therafter, D. Catheterise, drain bladder and retain the catheter therafter', 'role': 'user'}, {'content': "Answer: D \nExplanation: The patient in question is a case of posterior urethral injury. A urethral catheter may be passed into the bladder in many patients with a small, protal tear of posterior urethra. The catheter is maintained for 7 to 14 days. A voiding cystourethrogram is obtained when catheter is removed. Ref: Campbell's Urology, 7th Edition, Page 3109; Bailey and Love's Sho Practice of Surgery, 25th Edition, Pages 1364-65.", 'role': 'assistant'}]