Quiz functionality

You do not see the multistate object which has the correct and incorrect text in the Timeline panel?

Do you have similar slides like this? If yes, check if it is not on a previous slide, timed for the rest of the project. It cannot be on the master slide since you need to address it in the action.

I still can't figure out where the correct incorrect text isw coming from. It's not in any layer I see even if it is transparent.

Check the Object state panel for the feedback message. I would have a Normal state which is invisble (alpha and stroke set to 0. Then you do not need to hide/show the message.

From your screenshot it looks like the Smart Shape buttons on screen change the Object State of the Answer object when the button is clicked. 

If the object does indeed have States that should be visible, then the problem may be that the answer object is set to not be Visible in Output, i.e. it's hidden from view by default and needs to be SHOWN by an Advanced Action.  But your button is currently only executing ONE action, to change the state of the object.  If the object is also hidden by default, the button would need to execute at least TWO actions.  To achieve that you would need to create an Advanced Action and set the button to execute that action, rather than the way you currently have things set up.