*I need step by step explanation on how the answer in bold were gotten.* The following prices are available for call and put options on a stock priced at $50. The risk-free race is 6 percent and the volatility is 0.35. The March options have 90 days remaining and the June options have 180 days remaining. The Black-Scholes model was used to obtain the prices. Calls Puts Strike March June March June Use this information to answer questions 1 through 20. Assume that each transaction consists of one contact (for 100 shares) unless otherwise indicated. Answer questions 18 through 20 about a long box spread using the June50 and 55 options. 18. What is the cost of the box spread? a. $500 b. $2,018 c. $76 d. $484 e. none of the above 19. What is the profit if the stock price at expiration is $52.50? $16 b. $500 c. -$234 $250 e. none of the above 20. That is the net present value of the box spread? a. $9.84 b. $5.00 c. $16.00 d. $1.84 e. none of the above