Assessment Reattempt - not allowing student to submit no response

Hi Team, 
We are having constant issues with students not selecting "save and next" when completing their reattempt for self-marking questions. 

The students just click down the left side and do not save between answers - meaning that when they submit, they have questions that have no responses (automatically resulting in NYS).  

Is it possible to force them to save, or have a pop-up stating they have not changed their answers and do they want to review? 
It seems to do this on the first attempt, but not any reattempts.