(281)You are working on a 24 X 7 database. You want to design a backup strategy for your database that uses user managed backups.

You want to be able to perform all backups while the database remains online.

Which statement about performing user-managed backups in a 24x7 environment is true?

A. You must have change tracking enabled in your database

B. Your database must be running in NOARCHIVELOG mode

C. To back up a tablespace, it must be in backup mode

D. To back up a tablespace, it must first be taken offline

答案：（C）