challenge: Which polyhedra share a vertex arrangement with the U33?
  
  A. Small stellated truncated dodecahedron and the uniform compounds of 6 or 12 pentagrammic prisms
  B. Small stellated truncated dodecahedron and the uniform compounds of 3 or 9 pentagrammic prisms
  C. Small rhombidodecahedron and the uniform compounds of 6 or 12 pentagrammic prisms
  D. Large stellated truncated dodecahedron and the uniform compounds of 6 or 12 pentagrammic prisms
  Answer: 