I am developing a questionnaire where I need respondents to choose for which stages of the agricultural process they use mechanization. With the ones they chose, I already developed a roster in order to ask further questions about these specific stages. Nevertheless, I would also like them to answer why they did not choose to mechanize the other stages. For these, I would also like to develop a roster for the unselected options. Is there any way (coding, variable) that I can use in order to develop a roster with the unselected options from a categorical multi-select question?
Thanks a lot in advance.