How can I keep a respondent on the same question (or block of questions) until I get a good answer?

Do you need to track if they tried to answer with the unacceptable options? If you don't have to then you can add validation to the question that will only pass and allow them to move on if d, e, and f are not selected. See the sections on custom validation: https://www.qualtrics.com/support/survey-platform/survey-module/editing-questions/validation/

Best solution is that to throw an error message if they not selected a, b or c. Like "please recheck your answers" if they still not selected desired options you can terminate them.

thanks everyone (I'm sorry I don't know your names - only your handles). I will try those out! I thought it should have a simple answer, but I couldn't find it in the support documentation, and I couldn't remember. bstrahin - nope, don't need to track their "wrong" answers...I just want to keep them there until they pick a valid one. Of course i will have to add a "never mind" option so they can exit the form altogether... Thanks everyone!

Can you please let us know how displayErrorMessage function cab be used in Qualtrics (maybe we can use this function to show JS pop ups) for multiple validations on the same question.

Hey @Piyush_Sharma_88! If you have a new question, be sure to create a new post so there is more visibility!