Suppose that CC1, CC2, and CC3 are the prices of European call options with strike prices KK1, KK2, and KK3, respectively, where KK3>KK2>KK1 and KK3 - KK2 = KK2 - KK1. All three options have the same expiration. Show that 2CC2 CC1 + CC2. (Hint: Consider a strategy that is long one call with strike KK1, long one call with strike KK3, and short two calls with strike KK2. Show this strategy will always produce a non-negative future payoff.)