A student is organizing notes for a brief report: Notes: - A folding bridge prototype uses rigid panels joined by flexible hinges so it can be carried to temporary crossings. - A collapsible shelter prototype uses rigid panels joined by flexible hinges so it can be carried to disaster-response sites. - The bridge prototype supports pedestrians. - The shelter prototype protects supplies. The student wants to highlight a similarity in the engineering designs of the two prototypes. Which choice uses the notes most effectively for this purpose?