I always check "other" if "Caucasian" is the closest choice to my race. Then I put "American". I'm certainly not Irish like my paternal grandmother, nor Italian like my paternal grandfather, nor a Polish Jew like my maternal grandparents, and none of those are "Caucasian". I'd probably qualify for "White" but most of the racists who care don't traditionally consider any of the groups that my heritage is from "White". I'm an American by race, from European settler descent, and a United States citizen by nationality.