What are components called that protect conductors from overheating by opening the circuit?

The correct response identifies fuses and circuit breakers as the components designed to protect conductors from overheating by interrupting the circuit. These devices are essential for ensuring electrical safety within systems. Fuses contain a thin strip of metal that melts when excessive current flows through, thereby disconnecting the circuit and preventing potential overheating and fire hazards. Circuit breakers perform a similar function but can be reset after tripping, making them more user-friendly in many applications.

In contrast to the correct answer, switches are designed primarily to open and close circuits but do not provide protection against current overloads. Insulators serve to prevent electrical currents from undesirably passing through materials, rather than actively managing circuit overloads. Ground fault interrupters, while crucial for preventing electrical shock by detecting imbalances in electrical current, do not primarily serve the function of protecting conductors from overheating. Thus, fuses and circuit breakers stand out as the proper answer, as they are specifically engineered to address overheating and circuit interruptions due to excess current.