Elkins Corporation uses the perpetual inventory method. On March 1, it purchased $30,000 of inventory, terms 2/10, n/30. On March 3, Elkins returned goods that cost $3,000. On March 9, Elkins paid the supplier. On March 9, Elkins should credit (Points : 2)

inventory for $540. inventory for $600. purchase discounts for $540. purchase discounts for $600.