challenge: Where is the commune of Hem-Monacu located in relation to Amiens?
  
  A. Southeast of Amiens, by the banks of the river Marne
  B. Southwest of Amiens, by the banks of the river Seine
  C. Northwest of Amiens, by the banks of the river Oise
  D. Northeast of Amiens, by the banks of the river Somme
  Answer: 