You have an Azure subscription with 100 virtual machines. Which Azure portal blade should you use to quickly find underutilized VMs that could be moved to a less expensive service tier?

Azure Advisor is the correct choice because it provides personalized recommendations to optimize your Azure resources for cost, performance, reliability, operational excellence, and security. Specifically, it identifies underutilized virtual machines and suggests resizing or shutting them down to save costs. Monitor is incorrect because it focuses on collecting and analyzing telemetry data, not providing optimization recommendations. Metrics is a component of Monitor and provides raw performance data, not actionable advice. Customer insights is a data analytics service for understanding customer behavior, unrelated to VM optimization.