it's both. it started there...and they're called roman catholics because they were mostly romans. who else do you think was converted in rome...but romans? =/
Oh.My.God. You have some serious learning to do, child.
Roman Catholics are called that because (a) THAT flavor of Christianity was based in Rome and (b) "catholic" is a transliteration of the Greek "katholikos" which means "universal". It is synonymous with "orthodox", when used in religious terms. If you know anything about Christianity, you will know that there were originally several Christian Churches, based on geographical location, each autonomous but also part of the group. While, AT THE TIME, Roman Catholics were, for the most part, Latin-based, Greek Orthodox were Greek-based, etc., the expansion of empires demolished those lines of demarcation. There are Roman Catholics who are neither Roman nor Italian (I know Chinese Roman Catholics); there are Greek Orthodox who are not Greek (I know a GO couple who are Egyptian); There are Russian Orthodox who are not Russian (I know several personally who are African American). It is no longer (and has not been for centuries) based on nationality.
Seriously - you need to expand your education rather than tilting at windmills. I understand that you are young, but you are woefully lacking when it comes to the arguments you make.
My oldest is a college freshman this year, and if he came home with this kind of drivel? I'd smack him upside the head and tell him to sit down, shut up, read and listen to his professors. Oh, and to call his father. Must remember to do that!