Create a comment box for those survey questions that don't have a definitive categorization in their answers. In this attached example, my wife took a survey for a business we run together, but the question inadvertantly omitted the possibility that a product could be a digital product for sale instead of a physical product. There  was no easy way for my wife to answer, but she would have provided a clear answer had their been a box to leave comments. Make it easy on your vendors to give you answers.