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