【名词&注释】
树结构(tree structure)
[单选题]某事故树的最小径集为:Pl={Xl,X2,X4},P2={Xl,X2,X5},P3={Xl,X3,X6},P4={Xl,X3,X7},则结构重要程度为()。
A. I(1)>I(2)=I(3)>I(4)=I(5) B. I(1)>I(2)<I(3)>I(4)=I(5) C. I(1)>I(2)>I(3)<I(4)=I(5) D. I(3)>I(2)<I(1)>I(4)=I(5)