Triggers with checkboxes - multiple choice question

You need to put your correct and incorrect audio on your correct and incorrect layers. And you don't need triggers to toggle the radio buttons on quiz questions, that will happen automatically. When you select them as answer options in Form View, they become items that can toggle on and off (select and deselect).

I do think there's an issue with your "correct" feedback audio on 1.2, you should try reimporting it.

I updated your file and attached it here!