You can indeed replace answers by images as told. Know also that you can fill the background with an image. What is impossible on a question slide is the ability to use bookmarks, they are only available on content slides.

Hi! You mean to the options, right? Yes, you can add images to the multiple–choice options. Just check out the different design options for the multiple-choice question slides in the Visual properties on the right navigation panel. Under the Design Options, you will have designs that support adding images. Select a suitable design and replace the existing images with your own.