For managing a multi-cluster environment with a total of 2550 VMs, deploying a large 3-VM Prism Central instance is advisable. This setup provides the necessary scalability, redundancy, and performance to efficiently manage such a large number of VMs across multiple clusters. A 3-VM configuration ensures high availability and fault tolerance, crucial for maintaining consistent operations and management across the clusters.
References:
* Nutanix Bible: Prism Central Deployment
* Nutanix University: Scaling and Managing Large Environments

Ref:
https://portal.nutanix.com/page/documents/details?targetId=Web-Console-Guide-Prism-v510:wc-protection-dom

For the scenario with memory usage warnings and VDI performance issues, the best approach is to analyze and understand the memory usage patterns and demands on the system. Option D focuses on reviewing the Analysis page to monitor memory use trends and patterns, which is crucial for identifying peak usage times or processes consuming excessive memory. The mention of alerting with VDI workload demand implies the need to monitor and possibly adjust the VDI workload to better fit within available resources. Finally, analyzing current and future workload in the Capacity Runaway tab helps in understanding if the cluster resources are sufficient for the demand, which is critical in planning for capacity management and ensuring that such issues are mitigated moving forward.References: Nutanix Prism User Guide, Nutanix Community resources, VDI performance troubleshooting practices.