Which monitoring solution should you recommend to satisfy the monitoring requirements for App2?

Azure Application Insights is the correct choice because it's an Application Performance Management (APM) service specifically designed to monitor live web applications. It provides detailed insights into application performance, availability, and usage, which directly addresses the need to monitor App2's functionality and user experience. Azure Monitor for VMs (VM insights) focuses on the performance and health of virtual machines, not the applications running within them. Microsoft Sentinel is a Security Information and Event Management (SIEM) solution, primarily for security threat detection. Azure Monitor for containers (Container insights) is for monitoring containerized workloads, which is not specified for App2.