You can spread your multiple-choice options across up to five columns in the field configuration window.
Here's how:
Navigate to the form editor and locate your Multiple Choice field.
Hover over the field, and select the cog icon appearing on the right.
Once the field configuration window is open, scroll down to the option labeled "Number of columns".
Enter the number of columns that should be displayed (a number between 1 and 5).
Below this field you'll see one labeled "Number of columns on mobile". You can modify this value if you'd like smaller screens to have more/ less columns displayed.