Which one of the following classes of fire extinguishers is specifically designed for use on cooking fires?

Class K fire extinguishers are specifically designed to combat cooking fires that involve oils and fats, which are common in kitchens. These extinguishers contain agents that are particularly effective at extinguishing fires fueled by cooking oils, such as those found in fryers or stovetops. The unique formulation of Class K extinguishing agents serves to cool the flames and create a barrier between the fire and the fuel source, preventing reignition.

In contrast, Class A extinguishers are meant for ordinary combustible materials like wood or paper, Class B extinguishers target flammable liquids, and Class C extinguishers are suitable for electrical fires. While each class serves a specific purpose in firefighting, Class K is the only one tailored for the unique hazards associated with cooking fires, making it the correct choice for this kind of situation.