Why is performing an incremental backup of data from an Exadata Storage Server likely faster than backing up data from normal storage?

Why is performing an incremental backup of data from an Exadata Storage Server likely faster
than backing up data from normal storage?

A.
All data on the Exadata Storage Server is compressed.

B.
All backups from the Exadata Storage Server are compressed.

C.
Recovery Manager always uses more threads to perform backups from an Exadata Storage
Server.

D.
Offload processing finds only the changed blocks.

Explanation:
In incremental backup only the changed blocks are backup up.
Exadata Cell has offload capabilities that further speed up incremental backups.
Its offload capability combines with RMAN block change tracking to efficiently perform
large I/Os at the storage-tier level, returning only individual changed blocks for

incremental backups and increasing the backup performance of the system.
http://www.scribd.com/doc/39869360/MAA-Exadata-Backup-Whitepaper-Tech