What is the relationship between GMC Sierra and GMC 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.

GM Retail Sales Up 14 Percent Mon, Aug 3 2015 GM's four brands post their best combined July total and retail sales since 2007 Chevrolet delivers its best total and retail sales for any July since 2006 Chevrolet and GMC sold more than 86,000 pickups - best July since 2006 GMC Sierra and Canyon earned the highest Average Transaction Prices in their segments Buick sales up 18 percent on strong crossover demand Large planned reductions in daily rental deliveries continue

Answer: manufacturer