In the fragile queue library, can only the functions in that library change queue data?

$1$ point

Yes, you have to call one of those functions to change the values in the queue or queue structure

No$,$ the user can change not only the values in the queue but also in the queue structure

No$,$ but the user can only change values in the queue structure; the library functions must be called to change values in the queue

No$,$ but the user can only change values in the queue; the library functions must be called to change values in the queue structures