Which two statements about Cisco ESA clusters are true?

Which two statements about Cisco ESA clusters are true? (Choose two.)

A.
A cluster must contain exactly one group.

B.
A cluster can contain multiple groups.

C.
Clusters are implemented in a client/server relationship.

D.
The cluster configuration must be managed by the cluster administrator.

E.
The cluster configuration can be created and managed through either the GUI or the CLI.