Your database supports an online transaction processing (OLTP) workload and it needs to be up 24 x 7. You
want to perform a complete database backup by using RMAN.
Identify the minimum requirement for accomplishing the task.
A.
An RMAN channel must be configured to device-type disk.
B.
The database must be configured in ARCHIVELOG mode.
C.
Redo log groups must have at least two members each.
D.
All tablespaces in the database must be locally managed.
Explanation:
I guess B
OLTP systems usually remain online during backups and users may continue to access the system while the backup is running. The backup process should not introduce major performance degradation for the online users.
https://docs.oracle.com/cd/B28359_01/server.111/b32024/part_oltp.htm