Probably neither. The stinging hairs on the nettle would not be strong enough to penetrate the wasp's exoskeleton, and the wasp would have no reason to sting the nettle.
Nettles (Urtica dioica) sting to protect themselves, the question that you should be asking is How do nettles sting?
Well, now you asked...
The stinging structure of the nettle is very similar to...