If a Female Client Tells the Nurse of Extensive Plans

If a female client tells the nurse of extensive plans she has to harm the girlfriend of her ex-husband,what is the nurse's best action?

A) Try to talk with the client to convince her not to harm the girlfriend
B) Have the client sign a contract with you stating that she will not harm the girlfriend
C) Inform the ex-husband of the intentions of the client
D) Inform the girlfriend of the intentions of the client