In what was then the largest environmental enforcement case in US history, companies including industry leaders Caterpillar Inc, Cummins Engine Co, Mack Trucks and Volvo Truck Corp agreed to pay $US83.4 million in fines and reprogram the computers.
Take context from the input text and decide on the accurate relationship between 'Mack Trucks' and 'Truck' from the options provided.
Options: headquarters location, product/material produced, chairperson, original broadcaster