5. A call option on one share of GM stock with exercise price $80 is trading at $15 and a put option on one share of GM stock with exercise price $80 is trading at 8. Both options will expire one year from today. The current price of GM is $40. A treasury bill with par value equal to $80 will mature in exactly one year from today. The risk-free rate of return is 10%. You are considering two investment alternatives: Strategy I: taking long position on the stock and the put option; Strategy II: Taking long position on the Treasury bill and the call option. a. Write down the equation to find out the payoffs at expiration of Strategy I at different stock prices. b. Write down the equation to find out the payoffs at expiration of Strategy II at different stock prices. Given the information above, does put-call parity exist? Justify your answer. C