Which criteria must the Reliability Coordinator's monitoring systems satisfy?

The correct choice relates to the need for a Reliability Coordinator's monitoring systems to operate over a redundant infrastructure. In the context of NERC standards, redundancy is crucial because it ensures that there is a backup in place if a primary system fails. This is particularly important in reliability operations where continuous monitoring is essential for maintaining system stability and reliability of power supply.

A redundant infrastructure allows for immediate failover, thereby preventing any disruptions in real-time monitoring and analysis, which could lead to serious system failures or outages. It enhances the overall robustness of the Reliability Coordinator's monitoring systems, ensuring that they remain operational under various circumstances.

While cost-effectiveness, integration, and flexibility for upgrades are all valuable considerations in system design, they do not specifically address the critical requirement for resilience and uninterrupted operation that redundant systems provide in the context of reliability coordination. Thus, the emphasis on a redundant infrastructure aligns closely with the goals of ensuring continuous and reliable grid supervision.