Your multitenant container database, CDB1, is running in ARCHIVELOG mode and has two pluggable databases, HR_PDB and ACCOUNTS_PDB. An RMAN backup exists for the database. You issue the command to open ACCOUNTS_PDB and find that the USERDATA.DBF data file for the default permanent tablespace USERDATA belonging to ACCOUNTS_PDB is corrupted. What should you do before executing the commands to restore and recover the data file in ACCOUNTS_PDB? 

Answer options:

A. Place CDB1 in the mount stage and then the USERDATA tablespace offline in ACCOUNTS_PDB.B. Place CDB1 in the mount stage and issue the ALTER PLUGGABLE DATABASE accounts_pdb CLOSE IMMEDIATE command.
C. Issue the ALTER PLUGGABLE DATABASE accounts_pdb RESTRICTED command.
D. Take the USERDATA tablespace offline in ACCOUNTS_PDB.

D

* You can take an online tablespace offline so that it is temporarily unavailable for general use. The rest of the database remains open and available for users to access data. Conversely, you can bring an offline tablespace online to make the schema objects within the tablespace available to database users. The database must be open to alter the availability of a tablespace.