Which of the four combinations below will not give the same payoff as the other three? (a) Buy T-bills with face value of $40, sell a call with X = $40 and buy a call with X = $60 (b) Buy a put with exercise price of $60 and sell a put with an exercise price of $40 (c) Buy stock, buy a put with X = $40, sell 2 calls with X = $40, and buy a call with X = $60 (d) Sell a call with X = $40 and buy a call with X = $60