Which statement best describes the effect of idling on operating costs?

Answer: C — Idling Increases Operating Costs Due To Wasted Fuel

Idling uses fuel without doing any productive work, so you’re paying for energy that isn’t turning miles or providing service. That wasted fuel directly drives up operating costs. Keeping the engine running also adds unnecessary wear and maintenance over time, which can further increase expenses. So, the idea that idling increases operating costs due to wasted fuel is the best description. It’s not accurate to say idling reduces costs or has no effect, and while emissions are affected, there’s a clear cost impact from the wasted fuel and added wear.