A security administrator notices numerous unused, non-compliant desktops are connected to the network. Which of the following actions would the administrator most likely recommend to the management team?

Decommissioning is the most appropriate action because these desktops are both unused and non-compliant. Decommissioning involves removing systems from service, which eliminates the security risk posed by non-compliant devices and reduces the attack surface. Monitoring would only observe the problem without resolving it. Patching might address non-compliance if the issues were software-related, but it doesn't address the fact that the desktops are unused, making them unnecessary liabilities. Isolating them might prevent immediate harm, but it doesn't remove the unused, non-compliant assets from the environment, which is a best practice for security and asset management.