The price of a stock is 19 and the price of a 3-month European call option on the stock with a strike price of 20 is 1.

(i) Suppose that the risk-free interest is 4% per annum compounded continu- ously. What is the price of a 3-month European put option with a strike price of 20.

(ii) Suppose now that the risk-free interest rate is 5% per annum compounded continuously. Describe a possible strategy to make a risk-free profit.