What type of cargo is typically transported by hopper cars?

Hopper cars are specifically designed for transporting bulk materials in a convenient and efficient manner. The shape of these cars allows for easy loading and unloading through hatches on top and bottom. They are predominantly used to carry bulk commodities such as coal, cement, grains, and other similar materials. This capability makes them an ideal choice for moving large quantities of such heavy materials in an efficient manner without the need for additional packaging.

In contrast, palletized products, liquid chemicals, and general packages require different types of rail cars. For example, liquid chemicals are typically transported in tank cars that are specifically constructed to handle liquids, while palletized products and general packages are usually carried in boxcars that offer more protection and are designed for various sizes and shapes of goods. Therefore, the option indicating coal and cement aligns perfectly with the primary usage of hopper cars.