An administrator needs to assign a specific DNS server to an existing template variable. Where would the administrator go to edit a template variable at the device level?

"Managed Devices > Device Association" is used for associating devices with templates or device groups, not for editing the values of template variables.

"PDF Export under Panorama > Templates" is a functionality for exporting configuration data into a PDF format, not for editing or assigning variable values.

"Variable CSV export under Panorama > Templates" is a functionality for exporting variable data in CSV format, not for editing or assigning variable values.

To assign a specific DNS server to an existing template variable at the device level, the administrator must navigate to 'Panorama > Templates > Variables' to manage variable definitions and assign specific override values for devices or device groups. This allows for device-specific customization within a shared template.