Which of the following best states the author's main point? A. Pickett's study overturned the conventional understanding of why America engages in warfare. B. Pickett's study is valuable primarily because it provides a thorough understanding of the causes of American warfare. C. The rationale for American warfare is well documented. D. Pickett provides a cogent rationale for why America engages in warfare; however, he draws conclusions that the author does not fully support. E. Pickett's analysis of American military history provides the definitive historical record of the period from the Spanish-American War to World War I.