The U.S. did not agree with what Hitler was doing in Germany but the U.S. was trying to stay out of it but then when the Japanese bombed Pearl Harbor of December 7, 1941 they didn't have a choice anymore and entered WWII and eventually brought the war to an end on August 6, 1945 by dropping a 5-ton atomic bomb on the city of Hiroshima.
I think the answer is D seems the most likely reason
5) 3,500
6) 3.59
7) 4.7
8) 20
9) 1,250
10) 315
"The Man in the Arena" speech was delivered by president Teddy after being shot during a campaign