Stock prices

1) watch the following video:

https://www.nbcnews.com/nightly-news/video/oprah-s-got-a-new-favorite-thing–sends-weight-watchers-stock-soaring-547518531698

2)please answer the following questions regarding the video

a) How did the stock price immediately respond following these events? How has the stock price changed in subsequent years? What is it trading for today?

b)How might the present value free cash-flow method have been used to assess the fairness of the stock price?

c) What are the challenges of using the present value free cash-flow method in practice? How can accountants overcome these challenges?