GM also declined to comment on reports that in 2016 it would shift production of the Buick Verano sedan from Michigan to China; production of the Buick Regal from Canada to either China or Europe; and also start importing the Buick Cascade convertible from Europe.
What is the relationship between 'Buick Regal' and 'Buick' in the context of the input sentence.
Options: subsidiary, brand, position held, original broadcaster