A.) Because anti-Semitism was already very pervasive in German society at the time
Explanation:
Hitler´s rethoric was very successful because at his time in Germany the society was having hard problems with economy and recession because of the high tariffs that the winning countries of WWI had imposed on them, and the Jewish community was thriving and were seeing as stealing jobs and business form the German population, so he took advantage of that angryness and resentment towards the jewish population and told the German population that they were better, more intelligent, more capable than those that were "stealing their money and business" so in that environment of resentment and angryness, his rethoric thrived.
