Which four statements about users in Oracle Database 12c are correct?

A.
A common user cannot have the same name as any local user across all PDBs.

B.
A common user can be created only in the root container.

C.
A local user with the proper privileges can also create a common user.

D.
If a PDB is closed, the common and local users of the PDB are not visible.

E.
A common user with the proper privileges can create a common user by using the
CONTAINER=CURRENT clause.

F.
A common user is one that has the same username and authentication credentials across
multiple PDBs.