It is the Lightbox 03 and Lightbox 01 slides in the Earth project. I will navigate to your blog as well. Thank you so much!
Good news: both have a dedicated master slide.
Bad news: this is not at all a normal question slide. You'll see that the Quiz Properties panel is almost completely dimmed, you cannot use it. This is a custom slide, built with multiple buttons (those have a green timeline).
The correct and incorrect messages are in one multistate object. You may have found that it is hidden by default in the Timeline. Click the eye icon in the timeline to make them unhidden. See also:
http://blog.lilybiri.com/1-2-3-eye-buttons-mystery-2
I have done this in this screenshot. It is the top object.

Select the message you see, and click the State view button in its Properties panel.

You see another eye icon in the Properties panel, because feedback is hidden in output as well.
Hope you are aware of the fact that this is a pure Knowledge Check slide, it is not scored at all and you cannot transfer a score to a LMS.
If you need more explanation, just ask... The buttons trigger advanced actions (I would have used shared actions) but that will be bit too complicated to explain.