The Treaty of Versailles was the agreement that was labeled by the Nazis as unfair to Germany. The correct option in regards to all the options given in the question is option "1". Germany was not part of the conference in which the Treaty of Versailles was created and so the Nazis felt that it was unfair. When they did not want to be a signatory to the Treaty of Versailles, then the Allies threatened Germany that they would go to war again. The Germans also did not like several clauses included in the treaty. Clause like the War Guilt clause was totally hated by the Germans.