You are using Recovery Manager (RMAN) to perform backups. In which three situations would you perform a compressed backup?（）

• A、You are backing up to tape and your tape device performs its own compression.
• B、You are making image copies, and you have not enabled tablespace compression.
• C、You are using disk-based backups and disk space in your Flash Recovery Area, or other disk-based backup destinations are limited.
• D、You are performing your backups to some device over a network where reduced network bandwidth is more important than CPU usage.
• E、You are using some archival backup media, such as CD or DVD, where reducing backup sizes saves  media costs and archival storage.