If an electrode has resistance to ground of 25 ohms or less, what is required?

An electrode with a resistance to ground of 25 ohms or less meets the standard impedance requirements for proper grounding in electrical systems. This low level of resistance allows for effective grounding, which is essential for safety. When the resistance is at or below this threshold, it indicates that the grounding system is functioning well, allowing excess electrical current to safely dissipate to the ground.

Therefore, no additional measures, such as supplemental electrodes or increased grounding, are necessary when the resistance is compliant with this criterion. Regular inspection is always good practice but is not specifically required just because the resistance is at or below 25 ohms. Thus, the correct choice reflects that the grounding system is adequate as it stands.