Show correct and incorrect indicators on radio buttons / checkboxes
Select the radio button / checkbox you want to edit.
Click on the Correct or Incorrect Indicator property in the Properties panel
Choose the icon you wish to use.
To show the correct or incorrect indicator on particular answer option, create an action similar to the example below.
This action means that when the Submit button is clicked, if the correct option is selected (radio button option 2 in this example), show a correct indicator next to option 2. Otherwise, show an incorrect indicator next to the selected option.