4.9. Future prices of a stock are modeled with a 12-period binomial tree, each period being one month. You are given: (i) The tree is constructed based on forward prices. (ii) The stock's initial price is 50 . (iii) The continuously compounded risk-free interest rate is 4%. (iv) The stock pays no dividends. (v) =0.1 An American call option on the stock expiring in one year has strike price 70 . Calculate the price of the call option