A.SMON would automatically restore the lost file.
B.You would need to restore the whole database from the last backup.
C.You would need to restore the file from the last full database backup.
D.You would need to use flashback technology to restore the lost redo log member.
E.You would need to use Recovery Manager (RMAN) to restore the lost redo log member.
F.You would need to restore the missing log file by copying one of the remaining files from the same group.