Which of the following statements is true?

Here is testcase which explains why C & E are correct:

## Backup controlfile

RMAN> backup current controlfile;

Starting backup at 24-JAN-17
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=39 device type=DISK
channel ORA_DISK_1: starting full datafile backup set
channel ORA_DISK_1: specifying datafile(s) in backup set
including current control file in backup set
channel ORA_DISK_1: starting piece 1 at 24-JAN-17
channel ORA_DISK_1: finished piece 1 at 24-JAN-17
piece handle=/oracle/fra/OCP/backupset/2017_01_24/o1_mf_ncnnf_TAG20170124T161308_d8gnq593_.bkp tag=TAG20170124T161308 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 24-JAN-17

RMAN> list backup of controlfile;

List of Backup Sets
===================

BS Key Type LV Size Device Type Elapsed Time Completion Time
——- —- — ———- ———– ———— —————
1 Full 9.33M DISK 00:00:01 24-JAN-17
BP Key: 1 Status: AVAILABLE Compressed: NO Tag: TAG20170124T161308
Piece Name: /oracle/fra/OCP/backupset/2017_01_24/o1_mf_ncnnf_TAG20170124T161308_d8gnq593_.bkp
Control File Included: Ckp SCN: 1138736 Ckp time: 24-JAN-17

## Remove controlfile while database is running

SQL> select name from v$controlfile;

NAME
——————————————————————————–
+DATA_001/ocp/controlfile/current.260.934031875
/oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl

SQL> !rm /oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl^C

SQL> !ls /oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl
/oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl

SQL> !rm /oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl

SQL> !ls /oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl
ls: cannot access /oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl: No such file or directory

SQL> select status from v$instance;

STATUS
————
OPEN

## Connect to RMAN
oracle@s001tst-rhcsa|16:17|/oracle/oradump:rman target /

Recovery Manager: Release 11.2.0.4.0 – Production on Tue Jan 24 16:17:24 2017

Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved.

RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00554: initialization of internal recovery manager package failed
RMAN-06003: ORACLE error from target database:
ORA-00210: cannot open the specified control file
ORA-00202: control file: ‘/oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl’
ORA-27041: unable to open file
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3

## Stop instance and restore controlfile
## Even controlfile had been deleted the instance was still OPEN.

SQL> select status from v$instance;

STATUS
————
OPEN

SQL> shutdown immediate;
ORA-00210: cannot open the specified control file
ORA-00202: control file: ‘/oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl’
ORA-27041: unable to open file
Linux-x86_64 Error: 2: No such file or directory
Additional information: 3

SQL> shutdown abort;
ORACLE instance shut down.
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 – 64bit Production
With the Partitioning, Automatic Storage Management, OLAP, Data Mining
and Real Application Testing options

## Restore control file
RMAN> startup nomount

Oracle instance started

Total System Global Area 1369579520 bytes

Fixed Size 2253104 bytes
Variable Size 419434192 bytes
Database Buffers 939524096 bytes
Redo Buffers 8368128 bytes

RMAN> restore controlfile from ‘/oracle/fra/OCP/backupset/2017_01_24/o1_mf_ncnnf_TAG20170124T161308_d8gnq593_.bkp’;

Starting restore at 24-JAN-17
using channel ORA_DISK_1

channel ORA_DISK_1: restoring control file
channel ORA_DISK_1: restore complete, elapsed time: 00:00:01
output file name=+DATA_001/ocp/controlfile/current.260.934031875
output file name=/oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl
Finished restore at 24-JAN-17

## Here ‘alter databae open’ failed because no resetlogs was specified

RMAN> sql ‘alter database open’;

sql statement: alter database open
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of sql command on default channel at 01/24/2017 16:22:03
RMAN-11003: failure during parse/execution of SQL statement: alter database open
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open

RMAN> sql ‘alter database open resetlogs’;

sql statement: alter database open resetlogs
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of sql command on default channel at 01/24/2017 16:22:12
RMAN-11003: failure during parse/execution of SQL statement: alter database open resetlogs
ORA-01194: file 1 needs more recovery to be consistent
ORA-01110: data file 1: ‘+DATA_001/ocp/datafile/system.256.934031819’

RMAN> recover database;

Starting recover at 24-JAN-17
Starting implicit crosscheck backup at 24-JAN-17
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=1 device type=DISK
Finished implicit crosscheck backup at 24-JAN-17

Starting implicit crosscheck copy at 24-JAN-17
using channel ORA_DISK_1
Finished implicit crosscheck copy at 24-JAN-17

searching for all files in the recovery area
cataloging files…
cataloging done

List of Cataloged Files
=======================
File Name: /oracle/fra/OCP/backupset/2017_01_24/o1_mf_ncnnf_TAG20170124T161308_d8gnq593_.bkp

using channel ORA_DISK_1

starting media recovery

archived log for thread 1 with sequence 14 is already on disk as file +DATA_001/ocp/onlinelog/group_2.262.934031879
archived log file name=+DATA_001/ocp/onlinelog/group_2.262.934031879 thread=1 sequence=14
media recovery complete, elapsed time: 00:00:00
Finished recover at 24-JAN-17

RMAN> sql ‘alter database open resetlogs’;

sql statement: alter database open resetlogs

SQL> select status from v$instance;

STATUS
————
OPEN

SQL> select name from v$controlfile;

NAME
——————————————————————————–
+DATA_001/ocp/controlfile/current.260.934031875
/oracle/fra/OCP/controlfile/o1_mf_d8cp2mpq_.ctl