Utilize the input text as a context reference, choose the right relationship between Buick and General Motors from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

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.

Answer: parent_organization