What is the purpose of arc-fault circuit interrupters in residential wiring?

The purpose of arc-fault circuit interrupters (AFCIs) in residential wiring is to detect and interrupt arc faults, making option B the correct answer. Arc faults occur when electrical current creates an unintended arc due to damaged wiring, loose connections, or faulty devices. These arcs can generate excessive heat, potentially leading to electrical fires.

AFCIs continuously monitor the electrical circuit for signs of these hazardous arcs. When detected, they quickly interrupt the flow of electricity, significantly reducing the risk of fire caused by arcing. This protective function is crucial for enhancing safety in residential settings, especially in sleeping areas and living spaces where the risk of fire can pose serious dangers.

The other options refer to functions that are not the primary role of AFCIs. Preventing overloads relates more to circuit breakers, which protect against excessive current that can damage wiring. Providing voltage regulation is typically associated with devices like voltage regulators and transformers. Improving energy efficiency pertains to energy conservation practices or devices rather than the safety-focused operation of AFCIs. Thus, understanding the specific role of AFCIs underscores their importance in safeguarding residential wiring systems.