Which of the following offers the best analysis of why the United States entered World War ? (1 point) 1. The members of the Triple Alliance promised to help each other if attacked. 2. Great Britain entered into an agreement with France and Russia called the Triple Entente. 3. Archduke Franz Ferdinand was assassinated by a Serbian nationalist . 4. The U.S. was angered by German unrestricted submarine warfare.

4. The U.S. was angered by German unrestricted submarine warfare.