An administrator has implemented a hypervisor cluster with high availability enabled. They are
expecting that if any of the physical servers fail, the virtual servers will be transparently migrated to
other hypervisors in the cluster.
When the first hypervisor failure occurs, all of the hosted virtual servers appear offline to users as
they are moved to another host.
Which feature should the administrator have implemented to achieve their goal?

A.
Online Migration

B.
Load Balancing

C.
Resource Pooling

D.
Fault Tolerance