Your multitenant container database (CDB) containing two pluggable databases, PDB2_1 and PDB2_2, is running in ARCHIEVELOG mode. An RMAN backup exists for the databases. You issue the following…

Sequence 1,2,3,4,7,8 uses steps 3 and 4 in place of the restore and recover operations, which are not the correct RMAN commands for this recovery scenario, causing the recovery to be incomplete before the PDB open is attempted.

Sequence 1,2,5,6,7,8 follows the correct order by first establishing the RMAN connection to the CDB (1,2), then performing the restore (5) and recover (6) operations on the PDB, and finally opening the PDB and making data available (7,8).

Sequence 1,2,10,5,6,9 is also valid - after connecting (1,2), step 10 handles placing the PDB in the required state before the restore (5) and recover (6) operations, and step 9 properly opens the PDB with the necessary options to complete recovery.

Sequence 10,3,4,8,9 begins without first establishing the proper RMAN connection to the CDB root (steps 1 and 2), and applies subsequent commands in an order that skips the required restore step, making a successful recovery impossible.