Ann, an administrator, is configuring a two-node cluster that will be deployed. To check the cluster's functionality, she shuts down the active node. Cluster behavior is as expected, and the passive node is now active. Ann powers on the server again and wants to return to the original configuration. Which of the following cluster features will allow Ann to complete this task?

A. Heartbeat
B. Failback
C. Redundancy
D. Load balancing