Hi Davy,
I assume you are using a LayoutGroup component? If so, make the box in which you display your answer buttons larger. If that didn’t work try to use a LayoutElement component on each button and define a “Preferred Height” or “Min Height” there.
Layout Element | Unity UI | 1.0.0 (on each answer buttons)
Content Size Fitter | Unity UI | 1.0.0 (on the same game object as your LayoutGroup)
I hope this helped. 
See also:
- Forum User Guides : How to mark a topic as solved