Katie, a Historian, Is Conducting Research on the Character of the Present

Katie, a historian, is conducting research on the character of the present American government. During a lecture, she presents her view, which is in accordance with the Turner Thesis. Which of the following is Katie's lecture most likely to indicate?

A) The present American democracy was shaped by the American frontier experience.
B) The rise of capitalism in the United States was restricted by imperialism.
C) The political fiascos of the 1870s were the result of the underproduction of goods.
D) The United States lost access to geopolitical power by abstaining from invasions.
E) The purchase of Alaska was a decisive factor in modeling the present U.S. government.