challenge: What was the claim made by Phraortes, the Mede, that led to a rebellion in Media?
  
  A. He was Khshathrita, of the dynasty of Cyaxares
  B. He was the rightful king of the Persian Empire
  C. He was a descendant of the Achaemenid Empire's founders
  D. He was the son of Darius I
  Answer: 