4. In a look back option, at expiry the buyer is paid the maximum value of the stock over the life of the option minus the strike price. Use a binomial model with four periods to find the price of a look back option with So = 100, K = 100, d=0.9, u = 1.1, T = 1 year, and r = 0.05 per annum. 4. In a look back option, at expiry the buyer is paid the maximum value of the stock over the life of the option minus the strike price. Use a binomial model with four periods to find the price of a look back option with So = 100, K = 100, d=0.9, u = 1.1, T = 1 year, and r = 0.05 per annum