challenge: Where are René Oberthür's collections conserved?
  
  A. At Muséum national d'histoire naturelle, Museum Koenig, and Museo Civico di Storia Naturale di Genova
  B. Only at Museum Koenig and Museo Civico di Storia Naturale di Genova
  C. Only at Muséum national d'histoire naturelle
  D. At none of the above museums
  Answer: 