Which statement is true about the backup of the tools tablespace?

Consider the following scenario for your database: Backup optimization is enabled in
RMAN. The recovery window is set to seven days in RMAN. The most recent backup to disk
for the tools tablespace was taken on March 1, 2013. The tools tablespace is read-only
since March 2, 2013. On March 15, 2013, you issue the RMAN command to back up the
database to disk. Which statement is true about the backup of the tools tablespace?

A.
The RMAN backup fails because the tools tablespace is read-only.

B.
RMAN skips the backup of the tools tablespace because backup optimization is enabled.

C.
RMAN creates a backup of the tools tablespace because backup optimization is
applicable only for the backups written to media.

D.
RMAN creates a backup of the tools tablespace because no backup of the tablespace
exists within the seven-day recovery window.