What would be the first step to configure Flashback Database?

The database is currently running in the NOARCHIVELOG mode. What would be the first step to configure Flashback Database?

A.
Enable flashback logging.

B.
Start the database in the ARCHIVELOG mode.

C.
Issue the ALTER DATABASE FLASHBACK ON; command.

D.
Set the FAST_START_MTTR_TARGET initialization parameter.