Exercise 11.2.6 A rolling call comes with barriers H1 > H2 > · · · > Hn (all below the initial stock price) and strike prices X0 > X1 > · · · > Xn−1. This option starts as a European call with a strike price of X0.When the first barrier H1 is hit, the strike price is rolled down to X1. In general, on hitting each barrier Hi , the strike is rolled down to Xi . The option knocks out when the last barrier Hn is hit. Replicate this option with a portfolio of down-and-out options.