Which NetApp Storage Tier component works aggregate-wide on a FAS controller?

A.
Flash Pool

B.
Flash Disk

C.
Flash Cache

D.
Flash Accel

E.
Flash IO

Explanation:
http://www.netapp.com/us/system/pdf-reader.aspx?m=ds-3177-0512.pdf&cc=us

http://www.netapp.com/us/products/platform-os/flashpool.aspx
Flash Pool utilizes SSDs to enhance performance of disk aggregates.
Flash Cache is a controller-attached PCIe intelligent caching solution.
Flash Accel is a host-attached caching solution.
Flash Disk and Flash IO are ambiguous terms.