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

Furthermore, as Detroit automakers continue to rely on full-size trucks and SUVs for a majority of their profits, it's a good sign for investors that GM's Chevy and GMC brands sold more than 86,000 pickups in July -- GM's best figure since July 2006.

Answer: headquarters_location