Which class of fire is effectively targeted by dry chemical extinguishing systems?

Dry chemical extinguishing systems are particularly effective in combating class B and class C fires. Class B fires involve flammable liquids, such as oil, gasoline, and solvents, while class C fires pertain to electrical equipment. The dry chemical agents, often found in these systems, work by interrupting the chemical reaction occurring in the fire and cooling the fuel.

For flammable liquids, the dry chemical can create a barrier that prevents the fire from spreading and often leads to a more efficient suppression of the flames. In electrical fires, the non-conductive properties of some dry chemicals make them safe to use, allowing for effective extinguishment without the risk of electrocution.

Although dry chemical extinguishing systems can also assist with other classes of fires to some degree, their primary design and effectiveness are tailored for the challenges presented by flammable liquids and electrical equipment. Thus, option B accurately identifies the specific classes of fire that these systems target effectively.