Where should a CIO look to audit who modified an Azure resource and when the modification occurred?

The Azure Activity Log provides a historical record of events that occurred in your Azure subscription, including who performed an action, what action was performed, and when it happened. This makes it the ideal place for a CIO to audit resource modifications. Azure Cost Management focuses on cost analysis and optimization, not activity tracking. Azure Monitor collects and analyzes telemetry from Azure resources, but the Activity Log is specifically designed for control-plane events like resource modifications. Azure Policy helps enforce organizational standards and assess compliance, but it doesn't log individual modification events.