Suppose that c1, C2, and c3 are the prices of European call options with strike prices K1, K2, and K3, respectively, where K3 > K2 > K1 and K3 — K2 = K2 - K1. All options have the same maturity. Show that C2 Q 0.5(C1 -1- C3)

(Hint: Consider a portfolio that is long one option with strike price K1, long one option with strike price K3, and short two options with strike price K2.)