Which of the following offers the best analysis of why the United States entered World War I?

(1 point)
• Great Britain entered into an agreement with France and Russia called the Triple Entente.
• Archduke Franz Ferdinand was assassinated by a Serbian nationalist.
• The members of the Triple Alliance promised to help each other if attacked.
• The U.S. was angered by German unrestricted submarine warfare.

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