Reference: https://community.oracle.com/thread/451341

* SYS_CONTEXT
This is a twist on the SYS_CONTEXT function as it does not use USERENV. With this usage SYS_CONTEXT queries the list of the user's current default roles and returns TRUE if therole is granted.
Example:
SYS_CONTEXT('SYS_SESSION_ROLES', 'SUPERVISOR')
conn scott/tiger@pdborcl
SELECT sys_context('SYS_SESSION_ROLES', 'RESOURCE')
FROM dual;
SYS_CONTEXT('SYS_SESSION_ROLES','SUPERVISOR')
---------------------------------------------
FALSE
conn sys@pdborcl as sysdba
GRANT resource TO scott;
conn scott/tiger@pdborcl
SELECT sys_context('SYS_SESSION_ROLES', 'RESOURCE')
FROM dual;
SYS_CONTEXT('SYS_SESSION_ROLES','SUPERVISOR')
---------------------------------------------
TRUE

Explanation
Explanation:
B: SYSDG administrative privilege has ability to perform Data Guard operations (including startup and shutdown) using Data Guard Broker or dgmgrl.
D: SYSASM
The new (introduced in 11g) SYSASM role to manage the ASM instance, variable extent sizes to reduce shared pool usage, and the ability of an instance to read from a specific disk of a diskgroup E (Not A): SYSDBA is like a role in the sense that it is granted, but SYSDBA is a special built-in privilege to allow the DBA full control over the database Incorrect:
Not C: SYSKM. SYSKM administrative privilege has ability to perform transparent data encryption wallet operations.
Note:
Use the V$PWFILE_USERS view to see the users who have been granted administrative privileges.

C (not D): CONS_VPD_AUTO
Used to indicate to copy VPD policies automatically
* DBMS_RLS.ADD_POLICY
/ The DBMS_RLS package contains the fine-grained access control administrative interface, which is used to implement Virtual Private Database (VPD).DBMS_RLS is available with the Enterprise Edition only.
Note:
* CONS_USE_PK and CONS_USE_ROWID are constants usedas input to the
"options_flag" parameter in both the START_REDEF_TABLE Procedure and
CAN_REDEF_TABLE Procedure. CONS_USE_ROWID is used to indicate that the
redefinition should be done using rowids whileCONS_USE_PK implies that the redefinition should be done using primary keys or pseudo-primary keys (which are unique keys with all component columns having NOT NULL constraints).
* DBMS_REDEFINITION.START_REDEF_TABLE
To achieve online redefinition, incrementally maintainable local materialized views are used. These logs keep track of the changes to the master tables and are used by the materialized views during refresh synchronization.
* START_REDEF_TABLE Procedure
Prior to calling this procedure, you must manually create an empty interim table (in the sameschema as the table to be redefined) with the desired attributes of the post- redefinition table, and then call this procedure to initiate the redefinition.

Explanation/Reference:
Explanation:
Oracle Data Pump disable redo logging when loading data into tables and when creating indexes.
The new TRANSFORM option introduced in data pumps import provides the flexibility to turn off the redo generation for the objects during the course of import. The Master Table is used to track the detailed progress information of a Data Pump job.
The Master Table is created in the schema of the current user running the Pump Dump export or import, and it keeps tracks of lots of detailed information.