Identify three valid methods of opening, pluggable databases (PDBs).

Identify three valid methods of opening, pluggable databases (PDBs).

A.
ALTER PLUGGABLE DATABASE OPEN ALL ISSUED from the root

B.
ALTER PLUGGABLE DATABASE OPEN ALL ISSUED from a PDB

C.
ALTER PLUGGABLE DATABASE PDB OPEN issued from the seed

D.
ALTER DATABASE PDB OPEN issued from the root

E.
ALTER DATABASE OPEN issued from that PDB

F.
ALTER PLUGGABLE DATABASE PDB OPEN issued from another PDB

G.
ALTER PLUGGABLE DATABASE OPEN issued from that PDB

Explanation:
E: You can perform all ALTER PLUGGABLE DATABASE tasks by connecting to a
PDB and running the corresponding ALTER DATABASE statement. This functionality is provided
to maintain backward compatibility for applications that have been migrated to a CDB
environment.
AG: When you issue an ALTER PLUGGABLE DATABASE OPEN statement, READ WRITE is the
default unless a PDB being opened belongs to a CDB that is used as a physical standby
database, in which case READ ONLY is the default.
You can specify which PDBs to modify in the following ways:
List one or more PDBs.
Specify ALL to modify all of the PDBs.
Specify ALL EXCEPT to modify all of the PDBs, except for the PDBs listed.