You can keep your bulleted list with a little trick. This trick will work only if you don’t build your lists with the toolbar button, i.e. you format the list with a dedicated paragraph style turned into a list. For example, paragraph style List 1 linked with list (aka. numbering) style List 1. Note that for an unknown reason, this association is not done by default, you must set it in
Outline & Numbering tab of the paragraph style.
Then you customise list style List 1. Level 1 will be used for student choice and the bullet will be “ballot box” character, ☐. Level 2 is reserved for the answer and the bullet will be “ballot box with X,” ☒.
The trick is to set indents for both level 1 and level 2 identical so that you can’t distinguish them visually.
When you prepare the exam, the multiple choices are all typed under List 1 paragraph style.
When you write the answer sheet, all you have to do is copy/paste the choices. Set the cursor in front of the answer and press
Tab. The item is promoted to level 2 and its bullet changes.
Of course, in case your questions are using level 1, the choices must be “shifted” to level 2 and the answer to level 3. I let you adapt the scheme.