The correct options are
A The failure of the League of Nations
B Discontentment with the Treaty of Versailles
D The economic crisis that the First World War left in its wake
After WWI, the League of Nations was set up to maintain peace and prevent any future world wars. However, it failed to curb the rise of dictatorship in both Italy and Germany. Meanwhile, the Treaty of Versailles was considered unfavourable as it stripped away regions, army, and money from Germany. It was also resented by the Italians leading to the rise of Nazism and Fascism. The unemployment and inflation in post-war Europe also played a crucial role in exacerbating the crisis.