(A) Militarism
(B) Alliances
(C) Imperialism
(D) ** Nationalism
EXPLANATIONS BELOW
Concept note-1: -The Treaty of Versailles caused furious reactions in Germany. Germany had to pay huge sums of money to the countries it had fought in compensation for the damage. In addition, France, England, and the United States wanted to prevent Germany from becoming strong enough to start a new war.
Concept note-2: -The Treaty of Versailles punished Germany harshly because Allied powers, Great Britain and France especially, blamed Germany for starting the war and the subsequent death and destruction.
Concept note-3: -The peace treaty at Versailles with the Allies was considered as harsh and humiliating because of the following reasons: Germany lost its overseas colonies, 110th of its population, 13% of its territories, 75% of its iron and 26% of its coal to France, Poland, Denmark and Lithuania.