When an organization opts to deploy a VxRail cluster using a customer-supplied (external) vCenter Server instead of the embedded VxRail-managed virtual appliance, specific architectural and licensing boundaries must be accommodated during the design and planning phase. First, this model dictates that the customer must provide a separate, valid VMware vCenter Server license (Choice C), as the automated, bundled license included with the embedded deployment model is non-transferable to external management entities.
Second, because the infrastructure services are completely decoupled, the environment requires a fully functional, external DNS server (Choice B) with pre-established forward and reverse lookup records for all node management components, ESXi hosts, and the incoming VxRail Manager instance prior to initialization.
Third, the long-term maintenance paradigm shifts completely; the cluster uses customer-defined procedures for vCenter software upgrades (Choice D). This means the customer is independently responsible for patching and upgrading the external vCenter Server instance using standard VMware utilities like the vCenter Server Appliance Management Interface (VAMI) before initiating updates on the VxRail cluster components, effectively separating the external management platform from the automated VxRail Manager lifecycle management (LCM) framework.
References: Dell VxRail Deploy Study Guide; vCenter Server Choice and Planning; External Infrastructure Prerequisites.