Based on this from Appendix B to Reg C, I would report just what the applicant selected and not "I do not wish to furnish"
13. When an applicant provides the requested information for some but not all fields, you report the information that was provided by the applicant, whether partial or complete. If an applicant provides partial or complete information on ethnicity, race, and sex and also checks the “I do not wish to provide this information†box on an application that is taken by mail or on the internet, or makes that selection when applying by telephone, you must report the information on ethnicity, race, and sex that was provided by the applicant.
I can't speak to what investors want to see on a final 1003.