The answer is D.) Germans were angry about their punishment.
The allies point of view was that WW1 was cause by Germany and its allies and that Germany had to be "punished" for it with reparations. These reparations were a source of great dissatisfaction in Germany, contributed to its financial crisis in the period after the War, and paved a way for Hitler's government, because the frustrated and desperate people were more likely to accept an extreme government.