A . Schema owners indeed can grant privileges on objects in their schema to other users or roles, making this statement true.
B . Roles in Oracle can be granted both object and system privileges, making this statement true as well.
C . Not all types of schema objects have associated object privileges. For example, synonyms do not have object privileges because they are just aliases for other objects.
D . The DBA role is a powerful role, but creating roles can be done by any user granted the necessary privileges, not just users with the DBA role.
E . Object privileges on a table do not automatically apply to all synonyms for that table. Synonyms are separate objects that must have privileges granted explicitly.
F . The privilege to grant system privileges is controlled by the GRANT ANY PRIVILEGE system privilege, making this statement true.
Reference:
Oracle Database SQL Language Reference, 12c Release 1 (12.1): "Privileges" Oracle Database Security Guide, 12c Release 1 (12.1): "Administering User Privileges, Roles, and Profiles"