Explanation/Reference:
Explanation:
D: If a serious problem appears, roll back controller A. Controller A reboots and controller B takes over and runs the previous software version. When controller A recovers, it also runs the previous software version.
Incorrect Answers:
E: To roll back, locate a previous image and click on the rollback icon image: . You are asked to confirm that you wish to execute a rollback, and then the system reboots and executes the rollback. Unlike fail-safe rollback, you are not asked for further confirmation when the system reboots References: https://docs.oracle.com/cd/E51475_01/html/E52874/makehtml-id-13.html