Why was the Zimmermann Telegram so concerning to the United States that it swayed public opinion from neutrality toward intervention in World War I? A.
In the telegram between German officials, Germany detailed its plan to open a new front in the war by invading US territories in the Caribbean.

B.
In the telegram, Germany promised Mexico territory it lost in the Mexican-American War if it pledged to side with Germany if the United States entered the war.

C.
In the telegram, Germany requested Japanese assistance in capturing the US Territory of Hawaii to diminish the US presence in the Pacific.

D.
In the telegram between German officials, Germany detailed its plan to sink US passenger ships in the Atlantic if the United States did not remain neutral.