How do you respond to an inappropriate question on an interview?

[Natasha]

I don't think it was unprofessional for them to be curious about ur last name and ur background..but I do think .. that ur background (being polish) has nothing to do with your capability/qualifications for the job. If you didn't get the interview it was probably for some other reason.
I get asked about my last name a lot..because It's asian and I don't look asian at all. I look italian or brazilian, some kind of european and I constantly get asked about my last name..I don't take it the wrong way and neither should you. I just take it as like hmm..this isn't really an interview question..but they are just probably interested to know so I'll just be polite and tell them. They were probably just curious and asked about your name. Ps. Polish people are awesome.