C. Federalism
What is funny, is I'm am learning about this in school too!
A Roman legion (from Latin legio "military levy, conscription", from legere "to choose") normally indicates the basic ancient Roman army unit recruited specifically from Roman citizens. In reference to the early Roman Kingdom (as opposed to the Roman Republic or Empire), "the legion" means the entire Roman army.
Limiting the number of German soldiers and ships,
dividing Germany into a number of smaller countries,
prohibiting Germany from having submarines or an air force,
preventing Germany from gaining weapons and war materials