Which two are prerequisites for creating a backup-based duplicate database? 

Answer options:

A. connecting to the target database and a recovery catalog to execute the duplicate command
B. creating a password file for an auxiliary instance
C. connecting to an auxiliary instance
D. matching the database identifier (DBID) of the source database and the duplicate database
E. creating an SPFILE for the target database

AB

Reference: http://docs.oracle.com/cd/E11882_01/backup.112/e10643/rcmsynta020.htm#CHDEDFFH