3. Binomial trees for American options: a. Using a 2-step binomial tree with u = 1.20, d = 0.90, r = 0.10 per step, compare the prices of a European call and an American call both with X = 120 when So = 120. b. Using a 2-step binomial tree with u = 1.10,d = 0.95, r = 0.02 per step, compute the prices of a European call and an American call both with X = 14 when So = 12, assuming that a dividend of 2 liras is paid at time 1