Which EMC ControlCenter upgrade path is supported?

A.
5.1.1 multi-homed to 5.1.2 multi-homed
B.
Upgrade from ControlCenter 4.x to 5.0
C.
5.0.x to 5.1.x dedicated server to clustered server
D.
5.1.1 distributed server configuration to 5.1.2 single server configuration