Which statement BEST explains why United States entered World War I in 1917?

Question

Responses
A The Japanese launched a surprise attack on the U.S.The Japanese launched a surprise attack on the U.S.
B The U.S. citizens were calling for war against Germany.The U.S. citizens were calling for war against Germany.
C The Germans planned an attack of Mexico, an American ally.The Germans planned an attack of Mexico, an American ally.
D The U.S. had evidence of a threat to its national security.

Answer 1

The statement that BEST explains why the United States entered World War I in 1917 is:

D. The U.S. had evidence of a threat to its national security.

This encompasses several factors, including unrestricted submarine warfare by Germany, which threatened American shipping, and the Zimmermann Telegram, in which Germany proposed a military alliance with Mexico against the U.S. These events heightened concerns about national security and contributed to the decision to enter the war.