challenge: According to the advertisement, what was one of the uses of Zam-Buk ointment as an embrocation?
  
  A. Rubbing it into the hands to relieve arthritis
  B. Rubbing it into the muscles of the back, legs or feet
  C. Applying it to the scalp to stimulate hair growth
  D. Rubbing it into the stomach to aid digestion
  Answer: 