What do dry bulk cargo trailers typically transport?

Dry bulk cargo trailers are specifically designed for the transportation of materials that are not packaged and can flow freely, such as dry bulk commodities. This makes them ideal for carrying items like fertilizers, grains, and other similar products that are typically in powder or granular form. The design of these trailers allows easy loading and unloading of the materials, which is essential for maintaining efficiency in transporting bulk goods.

Options discussing refrigerated items and general freight involve categories that require different types of trailers; refrigerated items would necessitate temperature control, and general freight covers a broad variety of packaged goods that wouldn't be appropriate for bulk cargo trailers. Hazardous waste also requires specialized handling and packaging that goes beyond what standard dry bulk cargo trailers are intended to manage. Therefore, the correct answer accurately identifies the primary purpose and capability of dry bulk cargo trailers.