Your company has just purchased a new storage array to host your virtual machines (VMs). You
have connected the storage to each of your ESXi hosts and now wish to move some of the
running VMs to the new storage. Which vCenter feature would help you do this non-disruptively?

A.
Storage I/O Control

B.
High Availability

C.
Distributed Resource Scheduler (DRS)

D.
Storage vMotion

Explanation:
http://pubs.vmware.com/vsphere-51/index.jsp?topic=%2Fcom.vmware.vsphere.vcenterhost.doc%2FGUID-AB266895-BAA4-4BF3-894E-47F99DC7B77F.html