challenge: Which of the following alkaloids have been isolated from the foliage and wood of Zanthoxylum coco?
  
  A. Quinine, strychnine, and atropine
  B. Morphine, codeine, and papaverine
  C. γ-Fagarine, N-methylisocorydine, and skimminianine
  D. Caffeine, theobromine, and theophylline
  Answer: 