A stock has a price of $38 and an annual return volatility of 60 percent. The risk-free rate is 3.12 percent. Perform calculations in Excel. a. Calculate the European call and European put option prices with a strike price of $37.50 and a 90-day expiration. b. Calculate the deltas of the European call and European put. (Negative values should be indicated by a minus sign. Do not round intermediate calculations. Round your answers to 4 decimal places.)