A Unique Drag and Drop Experience

Hello,

I am going to include a link to a project I have published in Review 360.  Slide 2.7 is a DnD interaction I want to build in a unique way that I will probably use on all future interactions of this kind that I made.  I need to be able to do these things hopefully not with advanced triggers, since I need some practice with those still...

• When the learner drags an item to the incorrect drop location, I need the slide to immediately spit that item back to the side; this will indicate immediate feedback to the learner that the choice was wrong.
• Only when all 4 drops are correct should the user be able to "submit" for the final check.
• The learner should be free to move back to the previous slide, but the "home" button taking them back to the menu where they can start learning about the next kind of element should be grayed out until the end.
• Note: I think I can do the second and third bullet points, I just really need help with the first one.  Thank you!