What is the relationship between GMC and truck 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 Posts the Industry's Largest Retail Sales Increase on Double-digit Gains in Pickup and Crossover Sales Tue, Sep 1 2015 Chevrolet crossovers up for ninth consecutive month - best August ever Chevrolet truck sales up for 16th consecutive month Double-digit sales increase for GMC pickups Buick crossovers up 28 percent Cadillac SRX up 52 percent Commercial deliveries up for 22 consecutive months

Answer: product_or_material_produced