Which components are mandatory for a stretch MetroCluster to work?

A.
Clustered Heads, SyncMirror, Cluster Remote Option

B.
Clustered Heads, Brocade Switches, Cluster Remote Option

C.
Clustered Heads, Brocade Switches, SyncMirror

D.
Clustered Heads, SnapMirror Sync, Cluster Remote Option