What is the function of a lightning arrestor?

A lightning arrestor, also known as a surge arrester or lightning protector, serves the critical function of protecting electrical systems from lightning strikes and the accompanying surges of power. When lightning strikes an area, it can produce extremely high voltage and current levels that can cause severe damage to electrical equipment, disrupt power supply, or even create hazardous fire conditions.

The lightning arrestor is designed to safely divert or "arrest" this excess electrical energy away from the protected system, allowing it to ground safely without causing harm. By channeling the surge to the ground, the device helps to prevent damage to vital systems, such as power lines, transformers, and sensitive electronic devices.

This protection is essential for maintaining the integrity and reliability of electrical systems, especially in regions prone to thunderstorms. The other options suggest functions like enhancing power or increasing efficiency, which do not pertain to the primary role of a lightning arrestor. Its sole purpose is to protect against lightning-related damage, making the correct answer clear.