To which three elements is the size of the block change tracking file proportional?

To which three elements is the size of the block change tracking file proportional? (Choose three)

A.
Number of redo log groups.

B.
Number of DBWR process.

C.
Size of the database in bytes.

D.
Number of archiving destinations.

E.
Number of old backups maintained by the block change tracking file.

F.
Number of enabled threads in Real Application Cluster (RAC) environment.

Explanation:
The size of the block change tracking file is proportional to:
* The database size in bytes: the block change tracking file contains data representing every data file block in the database. The data is approximately 1/250000 of the total size of the database.
* The number of enabled threads: In a Real Application Cluster (RAC) environment, the instances update different areas of the tracking file without any locking or inter-node block swapping. You enable block change tracking for the entire database and not for individual instances.
* The number of old backups: The block change tracking file keeps a record of all changes between previous backups, in addition to the modification since the last backup. It retains the change history for a maximum of eight backups.
REF.: RMAN (
http://searchoracle.techtarget.com/searchOracle/downloads/10g_rman.doc)