Which three statements must be true for Cisco WLC to support roaming?

Which three statements must be true for Cisco WLC to support roaming? (Choose three.)
A. Controllers are in the same mobility group.
B. Controllers operate in different LWAPP modes.
C. ACLs are the same.
D. Virtual interface IP addresses are the same.
E. Controllers have different versions of code.
F. Controllers need to have the same hostname.