How many gallons should be ordered at a time for the Fill-er-Up gas station, which has a demand for unleaded gasoline at a constant rate of 100,000 gallons per year? The gas station pays $100 for shipping per order and currently buys gasoline for $3.75/gallon. The inventory carrying cost is 10% of the unit cost per year.
a) 20,000 gallons
b) 25,000 gallons
c) 30,000 gallons
d) 35,000 gallons