Which of the following is NOT a rank in the Air Force enlisted ranks?

The answer is correct because "Major General" is a rank that belongs to the officer ranks in the U.S. Air Force, not the enlisted ranks. The ranks in the enlisted tier typically include titles such as Airman, Airman First Class, Senior Airman, Staff Sergeant, Tech Sergeant, Master Sergeant, Senior Master Sergeant, and Chief Master Sergeant. Each of these plays a crucial role within the enlisted structure, but they are distinct from the officer ranks, which begin with Second Lieutenant and include ranks such as Major, Colonel, and General, such as Major General. Therefore, identifying Major General as not being an enlisted rank aligns with the understanding of how military ranks are categorized within the Air Force.