The PowerShell command in option D is the correct choice for automating the removal of switches from VLANs using the Cisco UCS Manager PowerShell module. This command uses environment variables to specify the VLAN name and switch identifiers, ensuring that the VLAN persists even when it is no longer associated with the switch port. The command structure allows for the removal of the VLAN association from the switch port without deleting the VLAN itself, thus maintaining the VLAN configuration for potential future use. References: The explanation is based on the Cisco UCS Manager PowerShell module documentation, which provides details on scripting and automation capabilities for managing Cisco UCS environments.