In the context of the input sentence, determine the relationship between 'Mack Trucks' and 'Truck'.
Options: product/material produced, business division, distribution format, founded by

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