Domicile is the place you plan to live in permanently. It is usually considered to be your home country.
If you actually plan on staying permanently in the US, you can select 'Yes' as an answer to that question, however in that case you'd be deemed as Full-Year Resident on State level and taxed as a resident on a State level. This only applies on state level and has nothing to do with your status as a resident or nonresident on a Federal level.