What is the relationship between GMC and Detroit in the context of the input sentence. Choose an answer from: 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