OPTIONAL FOR EXTRA CREDIT PROBLEM 12. (10 points. Consider a two period binomial model with parameters u = 1.10, d = 0.90. Suppose the per-period interest rate is r = 2%. Suppose the initial stock price is $100. (a) Calculate the value of an American put option on the stock with the maturity of two periods, and a strike price of $100. (b) Compute the early exercise premium. OPTIONAL FOR EXTRA CREDIT PROBLEM 12. (10 points. Consider a two period binomial model with parameters u = 1.10, d = 0.90. Suppose the per-period interest rate is r = 2%. Suppose the initial stock price is $100. (a) Calculate the value of an American put option on the stock with the maturity of two periods, and a strike price of $100. (b) Compute the early exercise premium