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.
Take context from the input text and decide on the accurate relationship between 'Volvo' and 'truck' from the options provided.
Options: position held, product/material produced, manufacturer, headquarters location