The Show action didn't work for me. I had to create an advanced action to pause the screen and show the Correct caption. One weird glitch is that I can't create the advanced action from the drag and drop slide. It will let me go through all the motions to create it, but then it won't be in the dropdown menu. So I have to go to another slide and create it.
The advanced action is:
Assign cpCmndPause with 1
Show [name of caption]
Then on your Drag and Drop panel under Action, go to On Success: Execute Advanced Actions and choose the action you just created.