Which is the wrong $($or the least correct$)$ statement?

Triggers are usually created in scheme level, thus they are stored in database system.

In the definition of a trigger, we must use the key word $$declare$$ before declaring any local variables

In general cases $($unless we define the trigger using AUTONOMOUS$\_$TRANSACTION option$),$ when we roll back the triggering event, all the inserted records by the trigger will be rolled back too.

Whenever a trigger is defined, no matter for statement level or row level, the system will create and populate two data structures, named as NEW and OLD.

In the conditional predicate case, if we define a trigger such as

INSERT OR DELETE OR UPDATE OF Salary on Employees for each row

$,$ the trigger will not be fired when manager$\_$id is changed.