challenge: What is a notable feature of the Rolandas Kalinauskas RK-7 Orange's design?
  
  A. A strut-braced high wing with a single engine in tractor configuration
  B. A low-wing configuration with retractable landing gear
  C. A tandem-seat cockpit with a variable-pitch propeller
  D. A strut-braced high wing with a single engine in pusher configuration
  Answer: 