(A) It revealed that Mexico was getting ready to enter the war on the German side
(B) ** It promised Mexico that Germany would help it reclaim territory in the United States if the United States entered the war against Germany
(C) Zimmerman was passing American secrets to Germany with the help of Mexican leaders
(D) The telegram contained secret messages sent by American leaders to its commanders on European battlefields
EXPLANATIONS BELOW
Concept note-1: -The telegram was considered perhaps Britain’s greatest intelligence coup of World War I and, coupled with American outrage over Germany’s resumption of unrestricted submarine warfare, was the tipping point persuading the U.S. to join the war.
Concept note-2: -In January 1917, British cryptographers deciphered a telegram from German Foreign Minister Arthur Zimmermann to the German Minister to Mexico, Heinrich von Eckhardt, offering United States territory to Mexico in return for joining the German cause.
Concept note-3: -In the message, Zimmermann instructed the German diplomats to approach the Mexican government, if United States entered the war in Europe, to offer an alliance between Germany and Mexico.
Concept note-4: -The State Department promptly sent a copy of the Zimmermann Telegram to President Wilson, who was shocked by the note’s content and the next day proposed to Congress that the U.S. should start arming its ships against possible German attacks.