You are using Stackdriver to monitor applications hosted on Google Cloud Platform (GCP). You recently deployed a new application, but its logs are not appearing on the Stackdriver dashboard.
You need to troubleshoot the issue. What should you do?

A. Confirm that the Stackdriver agent has been installed in the hosting virtual machine. B. Confirm that your account has the proper permissions to use the Stackdriver dashboard. C. Confirm that port 25 has been opened in the firewall to allow messages through to Stackdriver. D. Confirm that the application is using the required client library and the service account key has proper permissions.