What distinguishes stoneware from earthenware?

Stoneware is distinguished from earthenware primarily by its high-fire characteristics. Stoneware is fired at higher temperatures, typically between 2100 and 2300 degrees Fahrenheit, which leads to a dense, durable, and non-porous material. This high-temperature firing alters the composition of the clay, making it less susceptible to water absorption and better suited for functional ware like dishes and mugs.

The high-fire process gives stoneware its strength and ability to hold liquids without leaking, even without a glaze. In contrast, earthenware, which is fired at lower temperatures, remains porous and often requires glazing to make it waterproof and functional for holding liquids. Thus, the primary distinction lies in the firing temperature and its resulting qualities, which makes option C the correct one.