5. b

The fear of discovery would be the hardest part of life in the Secret Annex because of the primary reason of the Secret Annex: to hide from Nazis. When the Nazis discover these people, they will be killed because the Nazis' jobs are to exterminate the Jewish population. The party of Jews in the Secret Annex were hiding because they did not want to die and other things did not matter. So simply by using logic what will be the hardest part of life? Of course the fear of being found. Once they will be found, death lies ahead. I think death is something that is most feared because you can not come back to life or at least life on Earth. Being silent and being cramped with other people can not simply compare to death because being cramped and silence are really momentary and death is permanent.