单项选择题

某事故树的最小割集为:K1={X1},K2={X2,X3},K3={X2,X4,X5},则结构重要程度为()。

A.I(4)>I(2)>I(3)>I(1)=I(5)
B.I(1)>I(2)>I(3)>I(4)=I(5)
C.I(1)>I(5)>I(3)>I(4)=I(2)
D.I(5)>I(3)>I(2)>I(1)=I(4)