Removing unused elements from the Triggers pane

Hi everyone--

I am building the "Start" page for my course and I have run into a problem where I have a bunch of elements showing up in my Triggers pane that have no triggers associated with them (see attached screenshot). If I try to select them, the Trashcan icon is disabled so I cannot delete them.

Basically, these unused elements are the shapes that I used to create navigation buttons (i.e. BtnShap_Accreditation).  However, I grouped an image on top of these shapes, and I've configured the trigger on the grouped item (i.e. Btn_Accreditation).

As I will be sharing this Start page with our other IDs for their own use in future courses, I'd like to eliminate these unused elements from the Triggers pane so it makes more sense to them.

Any idea how to do this?

Thanks,

Jeremy