Select the word from the list that best fits the definition. hypothesis that states that the continents were once one large mass that broke apart. sea-floor spreading continental drift magnetic reversal magnetic minerals fossils

The answer to this is Continental drift. The reason its continental drift is because it was known that the continental drift was the reason the world split apart like for example United States was connected to Europe which was connected to Africa well when the Continental drift happened everything split apart now the only thats really connected that i know of is United States and Mexico. This right here is just a theory

But to cut this answer short your answer is Continental Drift. 
Hope this helped :) 

Italian workers migrated to northern provinces