Which of these caused the United States to become involved in World War I?
a. the German invasion of Poland
b. repeated violation of treaties by Japan
c. enemy bombing of American military bases
d. threats to American security made by Germany

Respuesta :

The correct answer is d. threats to American security made by Germany.

This refers to the fact that the German side attacked some submarines with American citizens on board despite assurances that Atlantic would remain neutral and safe.

D is correct I have just completed the test