You plan to create Azure Monitor security alerts for your Azure subscription. What resource should you create first to support those alerts?

An Azure Log Analytics workspace is the correct answer because it serves as the central repository for collecting, analyzing, and querying logs and metrics from various Azure resources, including security logs. Azure Monitor security alerts are configured based on queries against this collected data. Without a Log Analytics workspace, there's no central location to store the log data that Azure Monitor needs to evaluate for alert conditions. An Azure Storage account is used for general data storage, not specifically for real-time log analytics for Azure Monitor alerts. An Azure Event Hub is for streaming data ingestion, often used as an intermediary before data is sent to a Log Analytics workspace or other analytics services. An Azure Automation account is for automating tasks and runbooks, not for log collection and analysis for security alerts.