The current stock price is $50 and the stock pays no dividend. Each month, the stock price is either going up by 4% or going down by 2%. The current interest rate is an APR of 8% with monthly compounding. Consider a 5-month time interval (i.e. we are interested in payoffs occurring five months from now) and use the Binomial Lattice model with 5 timesteps (that is, each month is a period). (a) Find the explicit function of the payoff at maturity of a European (i.e. can only be exercised at maturity) bear spread option constructed with one unit of a call option with strike price $80, one shorted unit of a call option with strike price $20 and one unit of a zero-coupon bond with face value $60, all with same maturity, equal to 5 months. (b) Find the no-arbitrage price of this bear spread option. The current stock price is $50 and the stock pays no dividend. Each month, the stock price is either going up by 4% or going down by 2%. The current interest rate is an APR of 8% with monthly compounding. Consider a 5-month time interval (i.e. we are interested in payoffs occurring five months from now) and use the Binomial Lattice model with 5 timesteps (that is, each month is a period). (a) Find the explicit function of the payoff at maturity of a European (i.e. can only be exercised at maturity) bear spread option constructed with one unit of a call option with strike price $80, one shorted unit of a call option with strike price $20 and one unit of a zero-coupon bond with face value $60, all with same maturity, equal to 5 months. (b) Find the no-arbitrage price of this bear spread option