Which statement is true about unified auditing?

Which statement is true about unified auditing?

A.
The unified audit trail, by default, resides in a read-only table in the AUDSYS schema in the SYSAUX
tablespace.

B.
Only the CREATE, ALTER, and DROP statements are audited for all users, including SYS.

C.
Unified auditing is enabled only if the AUDIT_TRAIL parameter is set to NONE.

D.
The unified audit trail contains audit records only from unified audit policies and AUDIT settings.

Explanation:
https://docs.oracle.com/database/121/DBSEG/audit_admin.htm#DBSEG370