To manage multiple Azure subscriptions with a single set of access controls and policies, what should they implement first?

Management Groups are the correct answer because they provide a level of scope above subscriptions, allowing you to apply governance policies and access controls to multiple subscriptions simultaneously. This hierarchical structure enables efficient management and compliance across your Azure estate. Azure Lighthouse is incorrect because it's designed for service providers to manage resources across multiple customer tenants, not for managing multiple subscriptions within a single organization. Azure Resource Groups are incorrect because they are a logical container for resources within a single subscription, not across multiple subscriptions. Azure Advisor is incorrect because it provides recommendations for optimizing Azure resources, not for managing access controls or policies across subscriptions.