Which service should a developer use to query the latest inventory and properties of virtual machines for reporting?

Azure Resource Graph is the correct choice because it's designed for exploring and querying your Azure resources at scale across subscriptions. It allows you to efficiently query resource properties, including those of virtual machines, for reporting purposes. Azure AD (Active Directory) is for identity and access management, not resource querying. Azure Policy is for enforcing organizational standards and assessing compliance, not for querying resource inventory. Azure Monitor collects and analyzes telemetry data from Azure resources, but Azure Resource Graph is specifically optimized for querying resource metadata and properties for inventory and reporting.