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.
Explanation:
https://docs.oracle.com/database/121/DBSEG/users.htm#DBSEG99798