Which of the following is a key function of a surge protector?

A surge protector is fundamentally designed to safeguard electronics and electrical devices from voltage spikes, which can occur due to various reasons such as lightning strikes, power outages, or electrical fluctuations. When a sudden surge in voltage happens, a surge protector works by redirecting the excess voltage away from the connected devices, thereby preventing potential damage that could result from over-voltage situations.

The other options relate to different functions that are not relevant to surge protectors. Enhancing signal range pertains to amplification or repeaters, while increasing data transfer speed involves network protocols or equipment that manage data flow, such as routers and switches. Stabilizing network connectivity refers to devices or methods that ensure a reliable internet or connection experience, such as load balancers or redundant systems. Thus, the primary and essential role of a surge protector is to safeguard against voltage spikes.