Which command or commands should you execute next to allow updates to the flashback back schema?

Flashback is enabled for your multitenant container database (CDB), which contains two
pluggable database (PDBs). A local user was accidently dropped from one of the PDBs.
You want to flash back the PDB to the time before the local user was dropped. You connect to the
CDB and execute the following commands:
SQL > SHUTDOWN IMMEDIATE
SQL > STARTUP MOUNT

SQL > FLASHBACK DATABASE to TIME “TO_DATE (‘08/20/12’ , ‘MM/DD/YY’)”;
Examine following commands:
1. ALTER PLUGGABLE DATABASE ALL OPEN;
2. ALTER DATABASE OPEN;
3. ALTER DATABASE OPEN RESETLOGS;
Which command or commands should you execute next to allow updates to the flashback back
schema?

A.
Only 1

B.
Only 2

C.
Only 3

D.
3 and 1

E.
1 and 2

Explanation:
Example (see step23):
Step 1:
Run the RMAN FLASHBACK DATABASE command.
You can specify the target time by using a form of the command shown in the following examples:
FLASHBACK DATABASE TO SCN 46963;
FLASHBACK DATABASE
TO RESTORE POINT BEFORE_CHANGES;
FLASHBACK DATABASE TO TIME
“TO_DATE(’09/20/05′,’MM/DD/YY’)”;
When the FLASHBACK DATABASE command completes, the database is left mounted and
recovered to the specified target time.
Step 2:
Make the database available for updates by opening the database with the RESETLOGS option. If
the database is currently open read-only, then execute the following commands in SQL*Plus:
SHUTDOWN IMMEDIATE
STARTUP MOUNT

ALTER DATABASE OPEN RESETLOGS;