Triple

Given a phrase, classify it is english named entity (e.g., persons, organizations, works of art) in Latin script, or not (e.g., literals, dates, URLs, verbose phrases). For disambiguation, the statement where the phrase occurs as object is also given. Please return a JSON object with `phrase` (string, the phrase being analyzed) and `is_ne` (boolean, indicating whether the phrase is a Named Entity).

Phrase: XF-108 Rapier (prototype) | Statement: [North American Aviation, notableProduct, XF-108 Rapier (prototype)]

Target entity: XF-108 Rapier (prototype)
Context triple: [North American Aviation, notableProduct, XF-108 Rapier (prototype)]

• A. Douglas X-3 Stiletto
  The Douglas X-3 Stiletto was a slender, jet-powered experimental research aircraft of the early 1950s designed to investigate sustained supersonic flight and advanced aerodynamic concepts for future high-speed aircraft.
• B. Rockwell-MBB X-31
  The Rockwell-MBB X-31 was an experimental jet fighter demonstrator designed to test advanced thrust vectoring and high-angle-of-attack maneuverability technologies.
• C. Northrop X-21
  The Northrop X-21 was an experimental U.S. jet aircraft of the 1960s designed to test laminar-flow control technology for improved aerodynamic efficiency.
• D. Northrop X-4 Bantam
  The Northrop X-4 Bantam was a late-1940s American experimental jet aircraft designed to test the stability and handling of a tailless, swept-wing configuration at transonic speeds.
• E. Bell X-15
  The Bell X-15 was a rocket-powered experimental aircraft that set speed and altitude records in the 1960s and contributed crucial data to the development of crewed spaceflight and high-speed aeronautics.
• F. None of above. chosen
• G. Unsure - the case is ambiguous/there is not enough information to decide.

Generate a one-sentence description of the target entity. 
You are given a context triple in the form (subject, predicate, object), where the object is the target entity. 
# Instructions
Use the triple to infer relevant information about the entity. Describe the entity based on what is most defining, well-known. 
Avoid repeating the information from the triple, unless really essential.
# Response Format
Return only the sentence: "Description: [one-sentence description of the target entity]"

Entity: XF-108 Rapier (prototype)
Triple: [North American Aviation, notableProduct, XF-108 Rapier (prototype)]

The XF-108 Rapier was a proposed long-range, high-speed interceptor aircraft developed by North American Aviation for the U.S. Air Force during the Cold War but canceled before reaching production.

Target entity: XF-108 Rapier (prototype)
Target entity description: The XF-108 Rapier was a proposed long-range, high-speed interceptor aircraft developed by North American Aviation for the U.S. Air Force during the Cold War but canceled before reaching production.

• A. Douglas X-3 Stiletto
  The Douglas X-3 Stiletto was a slender, jet-powered experimental research aircraft of the early 1950s designed to investigate sustained supersonic flight and advanced aerodynamic concepts for future high-speed aircraft.
• B. Rockwell-MBB X-31
  The Rockwell-MBB X-31 was an experimental jet fighter demonstrator designed to test advanced thrust vectoring and high-angle-of-attack maneuverability technologies.
• C. Northrop X-21
  The Northrop X-21 was an experimental U.S. jet aircraft of the 1960s designed to test laminar-flow control technology for improved aerodynamic efficiency.
• D. Northrop X-4 Bantam
  The Northrop X-4 Bantam was a late-1940s American experimental jet aircraft designed to test the stability and handling of a tailless, swept-wing configuration at transonic speeds.
• E. Bell X-15
  The Bell X-15 was a rocket-powered experimental aircraft that set speed and altitude records in the 1960s and contributed crucial data to the development of crewed spaceflight and high-speed aeronautics.
• F. None of above. chosen