15. Consider a cash-or-nothing option in the binomial tree setting of Figure 1 with K = 90...

15. Consider a cash-or-nothing option in the binomial tree setting of Figure 1 with K = 90 and M = 10. Let denote the initial delta of the option, the delta following an up move in the stock price, and the delta following a down move. Show that even though the option has moved into-the-money.