Helen holds 900 shares of Fizbo Incorporated stock that she purchased 11 months ago. The stock has done very well and has appreciated $50/ share since Helen bought the stock. When sold, the stock will be taxed at capital gains rates (the long-term rate is 15 percent and the short-term rate is the taxpayer's marginal tax rate). Ignore the time value of money. a. If Helen's marginal tax rate is 35 percent, how much would she save by holding the stock an additional month before selling? b. What might prevent Helen from waiting to sell