You have a vSphere cluster managed by vCenter. One of the VMs is running a critical application
that is very sensitive to unplanned or sudden reboots. You wish to protect this VM from potential
data loss. Which of the following features will help you?

A.
vSphere Replication

B.
Fault Tolerance (FT)

C.
High Availability (HA)

D.
vMotion

Explanation:
http://en.community.dell.com/techcenter/virtualization/w/wiki/vmware-vsphere-faulttolerance.aspx