Drag and Drop and States and Triggers, OH MY!

On paper I've laid out an idea for a drag and drop activity, but I haven't been able to figure out the mechanics of it in Storyline yet. Any guidance would be greatly appreciated!

Picture a stack of paper sitting on a desk and four folders laid out on the floor. When you click the stack of paper, a sheet of notebook paper appears with a piece of information on it, and you need to drag the piece of paper into the appropriate folder where that information is stored. Once the notebook paper is dropped, it disappears from view. Click the stack of paper on the desk again and another sheet of notebook paper appears with a different piece of information on it that needs to be placed in the appropriate folder, and so on.

Is it possible to configure triggers on the stack of paper in such a way that click one makes paper 1 appear, click 2 makes paper two appear and so forth? I know how to configure the drag and drop and to make the paper disappear after dropping it, but I can't seem to wrap my head around the stack of paper.

Also...I'd like to be able to configure the exercise to wait until the learner finishes dropping all the notebook papers in the folders before 1. Letting them know if they dropped everything into the correct folder and 2. Telling them which folder was correct when they make a mistake.

Any suggestions?