A u se case model is

A、Adiagramwithstick-figureactorsconnectedtousecasesdrawninovals
B、Textflowsofeventsthatdescribethestepsanactortakestoaccomplishthegoalofausecase
C、Adiagramwithstick-figureactorsconnectedtousecasesdrawninovals,andtextflowsofeventsthatdescribethestepsanactortakestoaccomplishthegoalofausecase
D、Adiagramwithstick-figureactorsconnectedtousecasesdrawninovals,textflowofeventsthatdescribethestepsanactortakestoaccomplishthegoalofausecase,andassociateddocumentedbusinessrulesaffectingtheusecase