What kind of structure can be deduplicated?

A.
A disk

B.
An aggregate

C.
A FlexVol

D.
A qtree

Explanation:
http://hd.kvsconsulting.us/netappdoc/801docs/html/ontap/smg/GUID-B0C5894F-6D20-4210-A031-D5CD39C7A029.html (see data compression and deduplication)