One of the key advantages of using a Virtual Switching Extension (VSX) pair instead of two discrete switches for connecting servers, storage, firewalls, and other workloads is that both members in a VSX pair can be upgraded without any downtime for the workload (Option C). VSX technology provides advanced high availability features that allow for non-disruptive software upgrades, meaning that one switch in the VSX pair can be upgraded while the other continues to handle network traffic, thereby maintaining continuous operation of the connected workloads. This seamless failover capability ensures that there is no interruption to the critical services running on the network, making VSX an ideal solution for environments where uptime is paramount.