What is the relationship between 'Volvo' and 'Truck' in the context of the input sentence.
Options: owner of, brand, founded by, product/material produced

In what was then the largest environmental enforcement case in U.S. history, companies including industry leaders Caterpillar Inc., Cummins Engine Co., Mack Trucks and Volvo Truck Corp. agreed to pay $83.4 million in fines and reprogram the computers.
product/material produced