Final answer:
3. Cloud Monitoring. For application-level monitoring and SLO tracking with alerts, Cloud Monitoring is the ideal choice as it provides comprehensive insights into application performance and the capability to define and monitor SLOs.
Step-by-step explanation:
To configure application-level monitoring and monitor service-level objectives (SLOs) for applications, as well as to trigger alerts when SLOs are violated, you should opt for Cloud Monitoring. This product, also known as Stackdriver Monitoring, provides comprehensive visibility into the performance, uptime, and overall health of cloud-powered applications.
Cloud Monitoring helps you understand how your applications are performing in the context of end-to-end latency, error rates, and other critical metrics, and it enables you to set up custom dashboards and alerts based on the SLOs you define for your services.
It's also worth noting that while Error Reporting, Cloud Logging, and Cloud Trace are valuable tools, they serve different purposes: Error Reporting is for identifying and understanding application errors, Cloud Logging is for storing, searching, and analyzing log data, and Cloud Trace is for analyzing and viewing trace data to improve application performance.
However, Cloud Monitoring is the more comprehensive solution for setting up and tracking SLOs with alerting capabilities.