Which statement is true?

In your multitenant container database (CDB) with two pluggable database (PDBs). You
want to create a new PDB by using SQL Developer. Which statement is true?

A.
The CDB must be open.

B.
The CDB must be in the mount stage.

C.
The CDB must be in the nomount stage.

D.
Alt existing PDBs must be closed.