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
The commonest cause of an obliterative stricture of the membranous urethra is - 
Select and explain. 
A. Fall-astride injury, B. Road-traffic accident with fracture pelvis and rupture urethra, C. Prolonged catheterization, D. Gonococcal infection
B: Road-traffic accident with fracture pelvis and rupture urethra
Answer: B: Road-traffic accident with fracture pelvis and rupture urethra 
Explanation: Commonest cause of stricture in posterior urethra → Trauma with fracture pelvis
Commonest cause of stricture in anterior urethra → Straddle injuries (direct trauma to the perineal region).