Library preservationist: Due to the continual physical deterioration of the medieval manuscripts in our library' s collection, we have decided to restore most of our medieval manuscripts that are of widely acknowledged cultural significance, though this means that some medieval manuscripts whose authenticity is suspect will be restored. However, only manuscripts whose safety can be ensured during the restoration process will be restored, and manuscripts that are not frequently consulted by researchers will not be restored. If all of the library preservationist's statements are true, which one of the following must be true of the medieval manuscripts in the library's collection? ['The medieval manuscripts most susceptible to deterioration are those most frequently consulted by researchers.', 'All of the medieval manuscripts widely acknowledged to be of cultural significance are manuscripts whose safety can be ensured during the restoration process.', 'All of the medieval manuscripts whose safety can be ensured during the restoration process are frequently consulted by researchers.', 'Some of the medieval manuscripts whose authenticity is suspect are frequently consulted by researchers.']