B (not C): You can validate that all database files and archived redo logs can be
backed up by running a command as follows:
RMAN> BACKUP VALIDATE DATABASE ARCHIVELOG ALL;
This form of the command would check for physical corruption. To check for logical corruption,
RMAN> BACKUP VALIDATE CHECK LOGICAL DATABASE ARCHIVELOG ALL;
D: You can use the VALIDATE keyword of the BACKUP command to do the following:
Check datafiles for physical and logical corruption
Confirm that all database files exist and are in the correct locations.
Note:
You can use the VALIDATE option of the BACKUP command to verify that database files exist
and are in the correct locations (D), and have no physical or logical corruptions that would prevent
RMAN from creating backups of them. When performing a BACKUP...VALIDATE, RMAN reads
the files to be backed up in their entirety, as it would during a real backup. It does not, however,
actually produce any backup sets or image copies (Not A, not E).

Explanation
D: The database internally uses standard file system interfaces to create and delete files as needed for the following database structures:
Note:
* Using Oracle-managed files simplifies the administration of an Oracle Database. Oracle-managed files eliminate the need for you, the DBA, to directly manage the operating system files that make up an Oracle Database. With Oracle-managed files, you specify file system directories in which the database automatically creates, names, and manages files at the database object level. For example, you need only specify that you want to create a tablespace; you do not need to specify the name and path of the tablespace's datafile with the DATAFILE clause.
References:
http://www.oracle-base.com/articles/9i/oracle-managed-files.php
http://docs.oracle.com/cd/B10500_01/server.920/a96521/omf.htm

Explanation/Reference: https://docs.oracle.com/cd/B28359_01/server.111/b28274/sql_tune.htm#i36217

Note:
*An incremental level 0 backup backs up all blocks that have ever been in use in this
database.
*In a cumulative level 1 backup, RMAN backs up all the blocks used since the most recent level 0 incremental backup.
*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.

*To flash back a table to an earlier SCN or timestamp, you must have either the FLASHBACK object privilege on the table or the FLASHBACK ANY TABLE system privilege.
*From question: the OCP user has been granted the FLASHBACK ANY TABLE system privilege.
*Syntax
flashback_table::=