challenge: What event led to Pope John X crowning Berengar as Emperor in Rome in December 915?
  
  A. The defeat of the Magyars in Friuli
  B. Berengar's successful alliance with the local Italian rulers
  C. The fall of the city of Rome to the Saracens
  D. The Battle of the Garigliano, a victory over the Saracens
  Answer: 