You Have an Application in Production

Multiple Choice

You have an application in production. It is deployed on Compute Engine virtual machine instances controlled by a managed instance group. Traffic is routed to the instances via a HTTP(s) load balancer. Your users are unable to access your application. You want to implement a monitoring technique to alert you when the application is unavailable. Which technique should you choose?

A) Smoke tests
B) Stackdriver uptime checks
C) Cloud Load Balancing - heath checks
D) Managed instance group - heath checks