During an upgrade to vSphere 7.0, what must be done with an external Platform Services Controller?

When upgrading to vSphere 7.0 with an external Platform Services Controller (PSC), it is crucial to decommission the external PSC after the new vCenter Server Appliance (vCSA) is deployed due to changes in the architecture of vSphere 7.0. VMware has moved to a simplified architecture where vCenter Server can now host the PSC internally, eliminating the need for an external PSC.

As such, after deploying the new vCenter Server Appliance, the external PSC becomes unnecessary, and therefore, it should be decommissioned to ensure a clean environment. Keeping the external PSC could lead to complications, redundancy, and potential issues with managing the infrastructure.

Remaining options suggest actions that are either unnecessary or misaligned with the new architectural changes in vSphere 7.0, which emphasizes the importance of understanding VMware's advancements in its service management and infrastructure design.