Use the "up-down" binomial pricing method to derive call option values for the following conditions: A. S = 50, K = 54, r = 3%, t = .25, u = 1.5, d = .5 and there is only one step or "jump" before expiration. Assume this is an American option. Show your work. B. S = 50, K = 54, r = 3%, t = .25, u = 1.5, d = .5 and there are two steps or "jumps" before expiration. Assume this is an American option. Show your work. Also show whether you should exercise early at each node (f, fa, and f). Show your work. C. For Part A, how much is the "early exercise option" of this American option worth? D. For Part B, how much is the "early exercise option" of this American option worth?