Triple

Target class: experimental reusable rocket plane
Context triple: [Orbital Sciences X-34, instanceOf, experimental reusable rocket plane]

• A. reusable spaceplane chosen
  A reusable spaceplane is a winged spacecraft designed to take off, operate, and land multiple times like an aircraft while transporting payloads or crew between Earth and space.
• B. prototype rocket
  A prototype rocket is an experimental launch vehicle built to test and validate new propulsion, structural, and control technologies before full-scale production or operational deployment.
• C. fully reusable launch system
  A fully reusable launch system is a space launch architecture in which all major components (such as boosters, upper stages, and spacecraft) are recovered, refurbished, and flown again, minimizing expendable hardware and reducing per-launch costs.
• D. rocket-powered aircraft
  A rocket-powered aircraft is a type of airplane that uses rocket engines for primary thrust, enabling very high speeds and altitudes over relatively short flight durations.
• E. experimental aircraft
  An experimental aircraft is a prototype or testbed airplane designed and operated to evaluate new aerodynamic concepts, materials, systems, or technologies outside standard certified production models.
• F. None of above.