challenge: What type of aircraft did the Douthitt Strip primarily use for glider training?
  
  A. P-40 Warhawks and F-4 Corsairs
  B. C-47 Skytrains and Waco CG-4 unpowered gliders
  C. B-24 Liberators and P-38 Lightnings
  D. P-51 Mustangs and B-17 Flying Fortresses
  Answer: 