Meanwhile, the other Oshawa assembly line manufactures the current models of Chevrolet Impala, Buick Regal, Chevrolet Camaro and Cadillac XTS.In 2005, General Motors announced for the first time, the plans of closing the plant in 2008.
Take context from the input text and decide on the accurate relationship between 'Buick' and 'General Motors' from the options provided.
Options: operator, distributed by, chief executive officer, parent organization