An administrator account is granted the CREATE SESSION and SET CONTAINER system privileges. A multitenant container database (CDB) instant has the following parameter set: THREADED_EXECUTION = FALSE - Which four statements are true about this administrator establishing connections to root in a CDB that has been opened in read only mode? (Choose four.) 

Answer options:

A. You can connect as a common user by using the CONNECT statement.
B. You can connect as a local user by using the CONNECT statement.
C. You can connect by using easy connect.
D. You can connect by using OS authentication.
E. You can connect by using a Net Service name.
F. You can connect as a local user by using the SET CONTAINER statement.

ACDE

http://docs.oracle.com/database/121/ADMIN/cdb_admin.htm