B. Germany was blamed for causing World War I and C. They resented the reparations Germany had to pay.
The treaty of Versailles, signed on 28 June 1919, which put an end to the WWI (1914-18) was excessively harsh on defeated Germany. It set Germany as the aggressor and blame it for causing the war and consequently, it demanded Germans to pay for the losses and damage caused to the Allies, the winning side.
They also had to cede the territories they had obtained during the war, which reduced Germany's population and territory by about 10 percent, and they were demanded a series of measures aiming to prevent that they never again pose a military threat to the rest of Europe, such as the restriction of its army to 100,000 men, the elimination of the general staff, the manufacture of armored cars, tanks, submarines, airplanes, and poison gas was, etc.