All telecommunicated channels shall be periodically tested or monitored how?

The correct answer highlights the necessity for ongoing evaluation of telecommunication channels to ensure reliability and performance in the electric power sector. Monitoring or testing these channels on-line means that they are assessed while they are in active use, allowing for immediate detection of issues and ensuring that communications are stable and effective. This continuous oversight is crucial for meeting the operational demands of the electric grid, where timely and clear communication is essential for maintaining system reliability and responding to emergencies.

In the context of electric power operations, periodic testing or monitoring on-line enables real-time analysis, which can identify problems that may not be apparent through infrequent checks or during scheduled downtime. This proactive approach can help ensure that any issues with communication channels are resolved quickly, thereby supporting the robustness of the grid infrastructure.

While dedicated circuits and fiber optic channels may be important for ensuring strong communication links, they do not encapsulate the necessity for consistent, active monitoring. Two-party lines might refer to a different type of communication structure that does not specifically address the broader requirement for ongoing testing or monitoring in a telecommunicated setup. Thus, the emphasis on on-line periodic testing or monitoring stands out as the most suitable approach to maintain the integrity and functionality of communication channels in the electric power sector.