Which three are true concerning restoring of RMAN backups to primary and physical standby databases in a Data Guard environment? 

Answer options:

A. Backups of data files taken on the primary database may be restored on a physical standby database.
B. Backups of control files taken on the primary database may not be restored and used on a physical standby database.
C. Backups of SPFILEs taken on a physical standby database may not be restored on the primary database.
D. Backups of control files taken on a physical standby database may be restored on the primary database.
E. Backups of data files taken on a physical standby database may be restored on a primary database.
F. Backups of SPFILEs taken on the primary database may not be restored and used on a physical standby database.

CEF

C, F: All backup operations can be offloaded to a single standby database, except backups of the SPFILE. Backups of the SPFILE can only be restored to the database from which they were backed up. E: RMAN restores database files, over the network, from a physical standby database. As of Oracle Database 12c, RMAN lets you restore or recover files by connecting, over the network, to a physical standby database that contains the required files. You can restore an entire database, data files, control files, spfile, or tablespaces. Note: An Oracle database consists of one or more logical storage units called tablespaces, which collectively store all of the database`s data. Each tablespace in an Oracle database consists of one or more files called datafiles, which are physical structures that conform to the operating system in which Oracle is running. References: https://docs.oracle.com/database/121/SBYDB/rman.htm#SBYDB00755