Which event occurred in 1907 regarding military aviation?

The establishment of an Aeronautical Division in the US Army's Signal Corps in 1907 marked a significant milestone in the history of military aviation. This division was created to provide a dedicated focus on the development and application of aviation technology within military operations, recognizing the strategic advantages that aircraft could provide in warfare.

At that time, aviation was still in its infancy, but the formation of this division laid the groundwork for future advancements in military aviation, setting the stage for organized aerial reconnaissance, communication, and ultimately combat roles for aircraft. This initiative reflected an increasing awareness of the potential that aviation held for enhancing military capabilities, making it a foundational moment in the evolution of military air power.

In contrast, other choices either refer to concepts or advancements that are not associated with the timeline or do not accurately describe events relevant to military aviation in that specific year. For instance, hot air balloons had already been used in earlier conflicts, the first military airbase concept evolved later, and the first fighter jet was developed much later in the 20th century.