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

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

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

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

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

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

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