What protects the breaker points from damage by high-voltage surges?

The correct answer is the condenser, which is more commonly known in this context as a capacitor. In ignition systems, the condenser is critical because it stores electrical energy and releases it when needed, which helps to smooth out the electrical fluctuations in the circuit. When the ignition points (breaker points) open, a high-voltage surge can occur, potentially damaging these points. The condenser absorbs some of this surge, thus protecting the breaker points from excessive voltage and preventing arcing that can lead to wear and tear.

While the fuse, diode, and resistor serve important functions in electrical systems, they do not specifically address the protection of breaker points in the same capacity. A fuse is designed to blow and break a circuit in case of an overload, but it won't protect against surges while the system is operating. A diode allows current to flow in one direction only but does not help in smoothing out high-voltage surges. A resistor controls the flow of current but does not have the capacity to absorb voltage spikes effectively and protect delicate components like the breaker points.