Utilize the input text as a context reference, choose the right relationship between GMC 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.

Fold in the Silverado's upscale twin, the GMC Sierra, and General Motors ( NYSE:GM ) sold more full-size pickups in the first half of 2015 than mighty Ford ( NYSE:F ) .

Answer: parent_organization