B..
Wiping hands in that situation would generally be enough. Sometimes, people (like me) can be so sensitive it's not. BUT, that's why people like me carry an epipen everywhere. You did what you could, and yes I believe that is perfectly appropriate. We still have to go out and public and not everyone with a nut is going to be able to wipe their hands, or have that on their mind. I protect myself by carrying an epipen and being very careful. Most with serious allergies do.