Assume the Black-Scholes framework. Consider a 9-month at-the-money European put option on a futures contract. You are given the following information: The strike price of the option is 20. The volatility of the stock is 25% per annum. The continuously compounded risk-free interest rate is 10% per annum. a) What is the price of the put option at time 0? [4.5] b) If three months later the futures price is 17.7, what is the price of the put option at that time? [4.5]