I don't think they are forced into either a white / black category. Every questionnaire that
asks about race includes the choices: Asian, Hispanic, White, Black, or Other.
Probably, it's the Arabs who don't seem to have their own category.
They should expand it, but maybe it would look really nosy:
Asian, Hispanic, White, Black, Jew, Inuit, Middle Eastern.
I never liked those questionnaires. Why should it matter?