Your database is running in noarchivelog mode. One of the data files belonging to the system tablespace is
corrupted. You notice that all online redo logs have been overwritten since the last backup.
Which method would you use to recover the data file?
A.
 Shut down the instance if not already shut down, restore all data files belonging to the system tablespace 
from the last backup, and restart the instance.
B.
 Shut down the instance if not already shut down, restore the corrupted data file belonging to the system 
tablespace from the last backup, and restart the instance.
C.
 Shut down the instance if not already shut down, restore all data files for the entire database from the last 
backup, and restart the instance.
D.
 Mount the database, restore all data files belonging to the system tablespace from the last backup, and 
open the database.
ans c
Answer C is correct.