Hello Veronika. As far as I am aware it is still not possible to use Guest access with a questionnaire. However, if you want to put something on your front page then I suggest you explore using the Feedback activity which does allow guest access . Please see Feedback FAQ
Thank you Mary, I will try that tomorrow. For right now I created a guest user with a password. Since the module is only open in a controlled environment I thought I will let students sign in as guest with password to take the survey/questionnaire.
I appreciate your very fast response to my question/issue.