Which activity is audited by default and recorded in the operating system audit trail irrespective of whether or not database auditing is enabled? 

Answer options:

A. execution of SQL statements by users connected with the SYSDBA privilege
B. creation of a fine-grained audit policy
C. configuration of unified auditing mode
D. usage of the AUDIT statement

A

References - https://docs.oracle.com/cd/B28359_01/network.111/b28531/auditing.htm#DBSEG0622