Refer to the input text as context and select the correct relationship between 'GMC' and 'truck' from the available options.
Options: product/material produced, manufacturer, chief executive officer, developer

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
product/material produced