为自己加油

Examine these queries and their output:

An online RMAN backup of the CDB was taken an hour before Restore Point

R1 was created. You want to recover PDB1 to Restore Point R1.

How do you achieve this?  choose one

A.
Execute FLASHBACK PLUGGABLE DATABASE PDB1 TO RESTORE POINT R1by
Using RMAN
While connected to PDB1.
B.
Execute FLASHBACK PLUGGABLE DATABASE PDB1 TO RESTORE POINT R1by
Using SQL while
Connected to PDB1.
C.
Execute FLASHBACK PLUGGABLE DATABASE PDB1 TO RESTORE POINT R1by
Using SQL while
Connected to CDB$ROOT.
D.
Execute FLASHBACK PLUGGABLE DATABASE PDB1 TO RESTORE POINT R1by
Using RMAN
While connected to CDB$ROOT.
E.
This cannot be done due to the lack of a clean restore point.