Wire ripped after someone stole my cat converter. I believe it’s frm the o2 sensor. What to replace?

After my cat convertor was stolen, a wire was left severed under the car. I was told that the severed wire is likely from the O2 sensor, as it’s a common occurrence when these damm thieves steal the cat. I’m in the process of getting a new cat, and was hoping someone could explain what I should do about the presumably damaged (or stolen) O2 sensor.
In these type of scenarios, is it just the wire that needs to be replaced/repaired or do I need a new O2 sensor as well? I’m assuming new wiring will come with a sensor?
Thanks.

 

Will a replacement part of the downstream O2 sensor come with a new wire?

 

I’m having a DIY enthusiast friend installing it for me. He told me to get the parts, and he do it, but I didn’t ask about the parts cause I didn’t wanna look dumb. I’m Prius enthusiast.. just not a DYI Prius enthusiast.