Which storage system combination is supported in Cluster-Mode?

A.
a pair of FAS3270s and a pair of FAS3020s

B.
a pair of FAS3270s with a FAS3240 and a FAS6240

C.
a pair of FAS6280s and a pair of E7900s

D.
a pair of FAS6280s and a pair of FAS3240s

Explanation:
http://www.slideshare.net/NetApp/ar-scinetappontap811scaleoutv016-copy (see page
3, 4th para)