Anyone can use custom data sets by selecting them when creating a question under an Assessment Questionnaire. Only Admins can define the custom data set. This will walk you through where and how to define the custom data set and show you the result in the Questionnaire.
Note: Only "Multiple Choice - Single Selection" is possible when defining the type of custom data set; meaning, you can have as many answers to choose from but can only select one answer
Note: You'll notice the PlexTrac built-in Answer Sets can't be edited. New Answer sets can be edited (renamed, answers added/removed) however, at this time there is no way to delete them once created.
After defining at least two answers, you can save the custom answer set and it can be selected from the available Answer Types when building a question inside a Questionnaire