2. An economist writes a 1-period expectation model for valuing options. The model assumes that the stock starts at 20 and moves up or down by 25% in one year's time with equal probability. Assume interest rates are zero. (a) Using this expectation model what is the value of a call option struck at 22? (b) Now use the l-period model to calculate the risk-neutral probabil- ities and thus calculate the risk-neutral value of this call option. (c) (i) Calculate the percentage return on the option premium in the case the option ends in-the-money. (ii) What is the expected return? [Bonus: Can you explain your an- swer?)