<prompt> The commonest cause of an obliterative stricture of the membranous urethra is -Fall-astride injuryRoad-traffic accident with fracture pelvis and rupture urethraProlonged catheterizationGonococcal infection  <response>: Commonest cause of stricture in posterior urethra Trauma with fracture pelvisCommonest cause of stricture in anterior urethra Straddle injuries direct trauma to the perineal region. 