An administrator is upgrading a vCenter Server Appliance and wants to ensure that all the prerequisites are met. What action must be taken before upgrading the vCenter Server Appliance?

The VCSA upgrade process is initiated through a web-based installer that requires the Client Integration Plug-in to be installed on the administrator's workstation. This plug-in allows the browser to mount ISO images and communicate with local file system resources needed to deploy the new appliance. Without it, the installer cannot complete the necessary local operations.

The VCSA uses an embedded PostgreSQL database and does not require an external database client to be installed as a prerequisite.

ODBC connectors are required only for Windows-based vCenter Server installations using external databases, not for the appliance-based VCSA.

The Update Manager Plug-in is used for patching ESXi hosts and is unrelated to the vCenter Server Appliance upgrade process.