Unable to resize height dimensions of quiz answer options box

This is an old post but since the issue is still around, I'm sharing my thoughts:

The issue occurs when you use a master slide and have a 'Question Choice' placeholder on this master slide. (This is something Storyline generates automatically as an option when starting a new project - or when you click the 'Insert Slide Master' option and it generates some slide master options for you.)

As far as I'm aware, you cannot generate this 'Question Choice' placeholder yourself, as you only have a no- specific 'Content' placeholder you can add to a master slide. This 'Question Choice' placeholder has a standard 'Fixed size' setting which you cannot change like you can with text. You can change the height on the master slide, but that will be the fixed height for all your answer boxes on your question slides. And that is why your question slide will look weird if you try to adjust the height, because it will listen to the height of the master slide.

So there are some options: 
1. You can either make the 'Question Choice' placeholder as big as possible if you only need a little bit more space. (But it cannot go over the master slide edge because then it will give position issues.)

2.  My workflow:
Use the master slide with the 'Question Choice' placeholder as a template first, to make or import all your questions and lay-out them as you wish (but ignore the height of the answer option boxes for a minute).

Then duplicate the master slide and remove the 'Question Choice', and apply this lay-out to the slides with the problem. Now you can adjust the answer option boxes as you wish. (The reason I made the duplicate is so the other questions that don't have this problem, are not affected.)

Not the nicest workaround ever, but it worked for my workflow.