Which was a major cause for the entry of the u. s. into world war i? a) germany's invasion of belgium b) the desire to collect reparations c) russia's decision to leave the war d) germany's decision to resume unrestricted submarine warfare

The correct answer is:

d) Germany's decision to resume unrestricted submarine warfare

Explanation:

Wilson cited Germany's violation of its pledge to cease unrestricted submarine warfare in the North Atlantic and the Mediterranean, as well as its efforts to entice Mexico into an alliance against the United States, as his reasons for protesting the war.

The United States started the war because of the Germans' determination to continue the policy of unlimited submarine warfare, and the allegedly "Zimmerman telegram," stopped by the British, in which Germany drifted the concept of an alliance with Mexico.