One would be the rising greediness and not to mention demand for goods and another would be rebels were around during this time because of the Civil war starting soon.
It changed during World War 2 II. December 7, 1941, was a traumatic event in World history. The Japanese attacked the Americans at Pearl Harbor. Then Hitler declared war on the U.S. In 1945, the U.S. claims a world's primacy as the world's superpower by dropping two nuclear bombs on Japan and the Nuclear Age began.
I agree the answer is C. Good luck!
This is due to advances in communication