桑螵蛸散与天王补心丹两方组成中均含有的药物是（）

A.龙骨、人参

B.人参、菖蒲

C.菖蒲、远志

D.远志、当归

E.当归、石斛

setting redundant components in subsystem to handle with the risks brought by the defaults of original components, what kind of risk response strategy is this （）。

A.risk avoidance

B.risk acceptance

C.risk mitigation

D.contingency plan