What caused U. S. opinion to be against Germany?

A Acts of British cooperation

B. Acts of German aggression

C. Cultural differences

D. Economic interests

The correct answer is letter B.

Explanation: Rivalries between the two countries began to tighten after 1871, when Germany unified and became a more dominant European force.

The Monroe Doctrine, as the idea created by the American President James Monroe, who ruled between 1817 and 1825, was the author of the phrase "America for Americans." This political stance faced the recolonizing wave that swept Europe after Napoleon's defeat.