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
During TURP, surgeon takes care to dissect above the verumontanum to prevent injury to: 
Select and explain. 
A. Urethral crest, B. Trigone of bladder, C. External urethral sphincter, D. Prostatic utricle
C: External urethral sphincter
Answer: C: External urethral sphincter 
Explanation: Verumontanum is midline elevation on the posterior wall of the prostatic urethra. It acts as a surgical landmark. It lies immediately proximal to the external urethral sphincter. It thus serves as a distal landmark for prostatic resection in TURP to prevent injury to the external urethral sphincter.
"The verumontanum serves as a significant landmark to stop resection because the external urethral sphincter lies just distal to it." - Reoperative Pelvic Surgery By Richard P. Billingham p225