You have 200 Azure VMs and a recovery plan that fails them over to another Azure region. The recovery plan contains three manual actions; you want to replace one manual action with an automated process. Which of the following should you use to automate that action?

An Azure Automation runbook is the correct choice because it allows you to automate tasks and processes across Azure and non-Azure environments. In the context of a recovery plan, a runbook can be integrated to perform specific actions automatically, replacing a manual step. An Azure Desired State Configuration (DSC) virtual machine extension is used for configuring the state of VMs, not for automating actions within a recovery plan. An Azure PowerShell function is a serverless compute service for event-driven code execution, but an Automation runbook is specifically designed for broader process automation and integration with recovery plans. A Custom Script Extension is used to execute scripts on a VM during deployment or after, not for orchestrating actions within a recovery plan.