challenge: What is the origin of the name 'Poseidonis' in the Pusadian series by L. Sprague de Camp?
  
  A. It was given by the Romans to describe a mythical place
  B. It was the name given by the Greeks to the lost island continent of Pusad, which was a corruption of its original name
  C. It was the original name of the lost island continent of Pusad
  D. It was a name used by the inhabitants of the lost island continent
  Answer: 