Which mission showcased the potential of aerial refueling?

The Question Mark mission is significant for demonstrating the potential of aerial refueling, as it was the first time an aircraft successfully conducted continuous flight over an extended period through the use of in-flight refueling. This mission, carried out in 1929 by a Bell X-1 aircraft, involved refueling a single plane multiple times in the air, enabling it to remain airborne for over 151 hours without landing. This groundbreaking achievement illustrated how aerial refueling could extend flight time and operational range for aircraft, which was a pivotal development for military aviation.

In contrast, the other missions listed do not specifically emphasize or showcase the concept of aerial refueling. The Battle of Midway was a key naval battle in World War II, focusing on naval aviation strategies rather than aerial refueling advancements. Operation Overlord, also known as D-Day, involved the Allied invasion of Normandy, where air support and logistics played a role, but not the same focus on aerial refueling. The Battle of the Bulge involved significant ground combat operations during World War II without highlighting the use of aerial refueling technologies. Thus, the Question Mark mission stands out as the correct choice, illustrating a turning point in aviation capabilities.