Which two statements are true about dropping a pluggabl…

Which two statements are true about dropping a pluggable database (PDB)?

A.
A PDB must be in mount state or it must be unplugged.

B.
The data files associated with a PDB are automatically removed from disk.

C.
A dropped and unplugged PDB can be plugged back into the same multitenant container database (CDB)
or other CDBs.

D.
A PDB must be in closed state.

E.
The backups associated with a PDB are removed.

F.
A PDB must have been opened at least once after creation.