Explanation
A: In a cumulative level 1 backup, RMAN backs up all the blocks used since the most recent level 0 incremental backup.
E: Oracle Block Change Tracking
Once enabled; this new 10g feature records the modified since last backup and stores the log of it in a block change tracking file using the CTW (Change Tracking Writer) process. During backups RMAN uses the log file to identify the specific blocks that must be backed up. This improves RMAN's performance as it does not have to scan whole datafiles to detect changed blocks. Logging of changed blocks is performed by the CTRW process which is also responsible for writing data to the block change tracking file.
Note:
* An incremental level 0 backup backs up all blocks that have ever been in use in this database.

* optimizer_dynamic_sampling
OPTIMIZER_DYNAMIC_SAMPLING controls both when the database gathers dynamic statistics,
and the size of the sample that the optimizer uses to gather the statistics.
Range of values0 to 11

A, Not D:In a CDB, PUBLIC is a common role. In a PDB, privileges granted locally to PUBLIC enable all local and common users to exercise these privileges in this PDB only.
C:A user can only perform common operations on a common role, for example, granting privileges commonly to the role, when the following criteria are met:
The user is a common user whose current container is root.
The user has the SET CONTAINER privilege granted commonly, which means that the
privilege applies in all containers.
The user has privilege controlling the ability to perform the specified operation, and this
privilege has been granted commonly
Incorrect:
Note:
*Every privilege and role granted to Oracle-supplied users and roles is granted commonly
except for system privileges granted to PUBLIC, which are granted locally.

* Overview, example:
-Log into ncdb12c as sys
-Get the database in a consistent state by shutting it down cleanly.
-Open the database in read only mode
-Run DBMS_PDB.DESCRIBE to create an XML file describing the database.
-Shut down ncdb12c
-Connect to target CDB (CDB2)
-Check whether non-cdb (NCDB12c) can be plugged into CDB(CDB2)
-Plug-in Non-CDB (NCDB12c) as PDB(NCDB12c) into target CDB(CDB2).
-Access the PDB and run the noncdb_to_pdb.sql script.
-Open the new PDB in read/write mode.
*You can easily plug an Oracle Database 12c non-CDB into a CDB. Just create a PDB manifest file for the non-CDB, and then use the manifest file to create a cloned PDB in the CDB.
*Note that to plugin a non-CDB database into a CDB, the non-CDB database needs to be of version 12c as well. So existing 11g databases will need to be upgraded to 12c before they can be part of a 12c CDB.

RMAN> ALTER TABLESPACE sysaux OFFLINE IMMEDIATE;
RMAN> RESTORE TABLESPACE sysaux; RMAN> RECOVER TABLESPACE sysaux; RMAN> ALTER TABLESPACE sysaux ONLINE;
*Example:
While evaluating the 12c beta3 I was not able to do the recover while testing "all pdb files lost".
Cannot close the pdb as the system datafile was missing...
So only option to recover was:
Shutdown cdb (10)
startup mount; (1)
restore pluggable database
recover pluggable database
alter database open;
alter pluggable database name open;
Oracle support says: You should be able to close the pdb and restore/recover the system
tablespace of PDB.
*Inconsistent backups are usually created by taking online database backups. You can also make
an inconsistent backup by backing up data files while a database is closed, either:
/ Immediately after the crash of an Oracle instance (or, in an Oracle RAC configuration, all instances) / After shutting down the database using SHUTDOWN ABORT
Inconsistent backups are only useful if the database is in ARCHIVELOG mode and all archived redo logs created since the backup are available.
* Open the database with the RESETLOGS option after finishing recovery: SQL> ALTER DATABASE OPEN RESETLOGS;