You executed the following command in Recovery Manager （RMAN） to perform a backup of the DETTBS tablespace： RMAN> BACKUP TABLESPACE DETTBS； Under which conditions would this command execute successfully？ （）
- AThe database is in NOMOUNT state.
- BThe database is in ARCHIVELOG mode and the tablespace is online.
- CThe database is in ARCHIVELOG mode and the tablespace is offline.
- DThe database is in NOARCHIVELOG mode and the tablespace is online.
- EThe database is in NOARCHIVELOG mode and the tablespace is offline.