1. Közösség
2. News and Updates from Khan Academy
3. Update: Restart the practice activity you’re working on— introducing the “Start over” link!

Perhaps the button should not become active until at least one question is answered incorrectly?   To avoid accidental restarts. 

1. Közösség
2. SAT Questions and Feedback
3. Option to Reset SAT Individualized Practice Diagnostic Tests

I'd agree with prioritizing this... it shouldn't be hard.  I suspect a lot of people "try out" a first diagnostic, realize they aren't ready to continue, then come back a year or two later knowing ...