Determination of Safety Stock

"Jack then thinks - maybe my fuel usage isn't all that evenly spread out after all. Jack assigns probabilities to his fuel usage and determines that his expected shortage is 275 gallons and his expected excess is 300 gallons. Jack says it'll cost him another $0.40 per gallon to buy the fuel down the street if he runs out (i.e., stock out cost). How much safety stock should Jack maintain? a. 6,150 gallons b. 12,490 gallons c. 1,480 gallons d. 3,003 gallons "