challenge: What was the result of the collaboration between Facebook and Nielsen for the Secret deodorant page in 2009?
  
  A. Over 400,000 users became fans of the page, with 11 percent extremely likely to purchase
  B. Over 400,000 users became fans of the page, with 5 percent likely to purchase
  C. Over 1,000,000 users became fans of the page, with 20 percent likely to purchase
  D. Over 100,000 users became fans of the page
  Answer: 