单项选择题

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.