Suppose Amber Company's economic order quantity (EOQ) is 5,000 units. It has a total demand of 100,000 units per period, a carrying cost per unit of 20% of inventory value, a purchase price of $10, and fixed costs per order of $20. The total inventory cost of Amber is:

a) $100,000
b) $120,000
c) $150,000
d) $200,000