DETROIT - General Motor's (NYSE: GM) Chevrolet, Buick, GMC and Cadillac brands sold 272,512 vehicles in the United States in July 2015, a 6 percent increase and the four brands' best combined July since 2007.
Refer to the input text as context and select the correct relationship between 'GMC' and 'DETROIT' from the available options.
Options: distributed by, headquarters location, stock exchange, creator