Which Azure service provides a centralized view of system health and performance across resources?

Azure Monitor is the correct answer because it provides a comprehensive solution for collecting, analyzing, and acting on telemetry from your Azure and on-premises environments. It offers a centralized view of performance, health, and availability of your applications and infrastructure. Azure Advisor provides recommendations for optimizing resources, security, and cost, but not a real-time health overview. Azure Log Analytics is a component within Azure Monitor for querying and analyzing log data, not the overarching service. Azure Diagnostics is an older service primarily for collecting diagnostic data from Azure compute resources, which is now largely superseded by Azure Monitor's broader capabilities.