What type of circuit is designed to protect appliances from overload?

The selection of a circuit breaker as the correct answer stems from its primary function to prevent electrical overloads. A circuit breaker is a safety device that interrupts the flow of electrical current when it detects a fault, such as an overload or a short circuit. By doing so, it protects appliances from damage caused by excessive current, ensuring the longevity of the devices connected to the circuit.

Circuit breakers are designed to reset after they trip, meaning that once the fault is cleared, they can be re-enabled without the need for replacement. This is advantageous compared to fuses, which must be replaced after they blow. Circuit breakers provide a more user-friendly and efficient way to manage electrical safety.

In contrast, while a fuse also protects against overloads, it operates by melting and must be replaced once it has blown. Surge protectors focus on protecting against voltage spikes rather than overloads, and ground fault interrupters are designed to protect against ground faults and potential shock hazards rather than current overloads. Thus, the circuit breaker's features make it the most suitable choice for this specific purpose.