challenge: What is the percentage of valid signatures required to place a petition for an amendment to the Oregon Constitution on the ballot?
  
  A. Ten percent of the total number of votes cast in the last gubernatorial election
  B. Eight percent of the total number of votes cast in the last gubernatorial election
  C. Six percent of the total number of votes cast in the last gubernatorial election
  D. Five percent of the total number of votes cast in the last gubernatorial election
  Answer: 