1. (6.2) Which action by Germany prompted the United States to enter

World War I?

Answer: The Zimmerman telegraph.

Explanation:

The Zimmerman telegraph was about to get sent to Mexico and it was intercepted by Britain. They wanted to propose a military alliance between Mexico and Germany.

The United States entered the war because of the Germans' decision to resume the policy of unrestricted submarine warfare, and the so-called "Zimmerman telegram," intercepted by the British, in which Germany floated the idea of an alliance with Mexico.