Who was established as the Office of APM?

The correct answer, General Henry H. "Hap" Arnold, is significant because he played a crucial role in the establishment of the Army Air Forces, which later became the United States Air Force. His leadership and vision for air power significantly shaped military aviation during World War II and beyond. As a pioneering figure, Arnold was instrumental in advocating for air power as a vital component of national defense, and he emphasized the need for a dedicated air force separate from the Army. This vision laid the groundwork for what would eventually lead to the formalization and organization of air power, making his role as the Chief of the Army Air Forces vital in the history of military aviation in the United States.

The other individuals listed, while notable military leaders, do not have the same direct connection to the establishment of the Army Air Forces. General Dwight D. Eisenhower is primarily known for his leadership in World War II as Supreme Commander of the Allied Expeditionary Force. Colonel H.G. Reynolds's contributions are less widely recognized compared to Arnold's, and General George Patton is famously associated with armored warfare during the same era.