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
A patient is brought to the hospital with history of A 8 hours back. A few drops of blood were noted at the external urethral meatus. He has not passed urine and his bladder is palpable per abdomen. What is the probable diagnosis? 
Select and explain. 
A. Urethral injury, B. Rupture of bladder, C. Anuria due to hypovolemia, D. Ureteral injury with extravasation of urine into the retro peritoneum
A: Urethral injury
Answer: A: Urethral injury 
Explanation: The patient in the question following A has blood in the urethral meatus and a palpable abdominal mass both of which indicate the presence of injury to membranous urethra. Injury to membranous urethra occur following fracture of pelvis or avulsion of symphysis pubis. Rupture usually occur at the junction of membranous and prostatic urethra. Ref: Current Surgical Diagnosis & Treatment, Gerard M. Dohey, Page 1030-32; Undergraduate Surgery By A.K. Nan page 671.