A stock price is currently 20. Over each of the next two 6-month periods the stock price will either go up by 10% or down by 10%. The risk-free interest rate is 5% with continuous compounding. Price an Asian call option with strike K=19 and payoff (5 - K)+, where S = 1.3 (S_0 + S_1 + S_2) and S_0, S_1 S_2 are stock prices at times 0, 1/2, and 1, respectively