Which statement is true about using the Database Upgrade Assistant (DBUA) to upgrade your database from Oracle Database 11g to Oracle Database 12c? 

Answer options:

A. It terminates if the SYSTEM tablespace in the source database is not autoextensible.
B. It automatically makes necessary changes to Oracle environment variables.
C. It automatically enables unified auditing in the upgraded database.
D. It automatically adds new data files if there is not enough disk space to grow.

D

References: https://docs.oracle.com/cd/E18283_01/server.112/e17222/upgrade.htm#insertedID5