Which two are true about instance recovery for a database that is open in read write mode? (Choose two.)

A. Only the CURRENT REDO log group is required to perform instance recovery.

B. The database opens after the roll forward phase of instance recovery has completed.

C. It always occurs during instance startup performed immediately after a SHUTDOWN ABORT.

D. It is always performed when opening a database.

E. No users can log on until instance recovery has completed.

F. It is guaranteed to complete within fast_start_mttr_target number of seconds.