What was one reason the German army began to decrease in size? German soldiers left to join the Allied forces.
German allies provided fewer and fewer troops.
Germany was unable to pay its soldiers enough money.
Germany was unable to replace US soldiers who had left.

German soldiers left to join the Allied forces.

Explanation: The German military was frustrated by the feeling that they had been betrayed by the political leaders who chose to end the war. In 1919, the German government was weak because leaders fled government positions as the war was closing. The treaty required the military to keep its navy, army, and air force small.

   I'm sure 100 percent about the explanation but not sure about the answer.                           And I hope this helped

i believe the answer is c

did you check the study guide?