Before 1947, which military branch was responsible for air operations?

Before 1947, the U.S. Army Air Forces was responsible for air operations. This organization was a significant component of the U.S. Army during World War II, with its primary mission focused on strategic bombing, close air support, and air transport. The Army Air Forces developed tactics and strategies for air warfare and played a crucial role in various military campaigns.

The establishment of the U.S. Air Force as an independent branch of the military on September 18, 1947, formalized air operations outside of the Army structure. Prior to that, all air units, including those that would later become the core of the Air Force, were managed under the Army's command system. Thus, the Army Air Forces was the designated branch tasked with overseeing and executing air operations during that period, making it the correct answer.