A systems administrator deployed a new application release to the green stack of a blue-green infrastructure model and made the green stack primary. Immediately afterward, users began reporting application issues. The systems administrator must take action to bring the service online as quickly as possible. Which of the following is the FASTEST way to restore the service?

A. Reboot all the servers in the green stack
B. Failback to the blue stack
C. Restore from backups
D. Troubleshoot and resolve the application issues