Based on the passage, all of the following are mentioned as casting doubt on Mackay's thesis EXCEPT A. Accounts of tulip mania came from limited and not totally credible sources B. Trade of tulips was limited to a certain group of people C. There was a dearth of information relating to the price of tulips throughout the mania D. The nobility ceased to trade in tulips once prices began to increase sharply E. The rise in the price of tulips corresponded with the changes in the Thirty Years War