Explanation
The cluster feature that will allow Ann to complete her task is failback. A cluster is a group of servers that work together to provide high availability, scalability, and load balancing for applications or services. A cluster can have different nodes or members that have different roles or states. An active node is a node that is currently running an application or service and serving requests from clients. A passive node is a node that is on standby and ready to take over if the active node fails. A failover is a process of switching from a failed or unavailable node to another node in a cluster. A failback is a process of switching back from a failover node to the original node after it becomes available again. Failback can be automatic or manual depending on the cluster configuration.

RAID 6 Disk Striping with Double Parity
The RAID 6 design distributes data across a minimum of four HDDs the same way that RAID 0 and RAID 5 do, but it also distributes parity information across two disks. The result is that a RAID 6 array can recover data even with the failure of two HDDs. Reads are quick, like RAID 5, but writes are slower due to the duplication of the parity data. It is a good general solution as long as the performance hit on write tasks is not a problem for your environment.
RAID 6 requires a minimum of four HDDs.

Explanation
The sc command is used to create, delete, start, stop, pause, or query services on a Windows OS. It can also be used to register a new service by using the create option.References:https://docs.microsoft.com/en-us/windows-server/administration/windows-commands/sc-crea