Dan Kieffer of PACCAR Inc., speaking for a group of heavy-duty North American truck manufacturers including Volvo and Daimler, said, “Unnecessarily stringent engine standards will only exacerbate today’s trend of delaying new truck purchases,” and consequently keep older, not-as-clean trucks on the road.
Utilize the input text as a context reference, choose the right relationship between 'PACCAR' and 'truck' from the options.
Options: director/manager, distributed by, owned by, product/material produced