Which NetApp Virtual Storage Tier component works at the host level?

A.
Flash Pool

B.
Flash Disk

C.
Flash Accel

D.
Flash Cache

E.
Flash IO

Explanation:
http://www.netapp.com/us/system/pdf-reader.aspx?m=ds-3366.pdf&cc=us
Flash Accel utilizes server-based flash storage as cache for the host.