Astrid is an avid fan of hunting and she is buying a new gun for her hobby. She could get a new AR-15 rifle, which has a price of $1800 and an annual ammunition cost around $100. Alternatively, she could get a new revolver which only costs $1200 but the annual ammunition cost will be about $150. Assume that both guns will last 20 years. Astrid plans to buy ammunition at the beginning of each year (starting now) and discounts future cash flows at 15% EAR. Which of the following statements is correct? Select one: O a. The present value of all costs related to the revolver is $1200 + $150-20 = $7200 O b. The present value of all costs related to the rifle is $1800 + PV(PMT= -$100, NPER=20, RATE=15%, FV=0) = $2425.93 O c. To determine which option is cheaper, Astrid should only consider ammunition costs and ignore the costs of guns ($1800 and $1200) because these are sunk costs O d. To find the present value of all costs related to the revolver, Astrid should discount future cash flows using a nominal interest rate which is greater than the 15%EAR O e. None of the above is correct