what statement BEST explains why US entered World War 1 in 1917?

The United States entered World War I in 1917 primarily due to unrestricted submarine warfare by Germany, which threatened American shipping and lives, exemplified by the sinking of the Lusitania. Additionally, the interception of the Zimmermann Telegram, in which Germany proposed a military alliance with Mexico against the U.S., heightened concerns over national security. These factors, combined with growing economic ties to the Allies and a desire to promote democracy, ultimately compelled the U.S. to join the conflict.