I think that it depends where the interview is. For instance, I've been asked that at the Texas schools, because I think that they want to know how committed you are to staying instate. I think that lower-tier schools might ask you to try to see if they're a safety for you. I would just be honest, but don't be afraid to vague things up a little (e.g. I applied to a wide range of schools in the Northwest, etc.).