(A) The Selective Service Act
(B) The Monroe Doctrine
(C) The Sussex Pledge
(D) ** The Zimmerman telegram
EXPLANATIONS BELOW
Concept note-1: -In January of 1917, British cryptographers deciphered a telegram from German Foreign Minister Arthur Zimmermann to the German Minister to Mexico, von Eckhardt, offering United States territory to Mexico in return for joining the German cause.
Concept note-2: -The “Zimmerman Telegram” promised the Mexican Government that Germany would help Mexico recover the territory it had ceded to the United States following the Mexican-American War. In return for this assistance, the Germans asked for Mexican support in the war.
Concept note-3: -He proposed that the two nations strike an alliance; if Mexico waged war against the United States, thereby distracting Americans from the conflict in Europe, Germany would lend support and help Mexico reclaim Texas, New Mexico and Arizona.
Concept note-4: -Germany promised to help Mexico take back land the United States had taken from Mexico in the Mexican–American War. These places were Texas, New Mexico, and Arizona. Germany wanted Mexico to enter the war so America would be too busy to help the enemies of Germany.