At a lump-sum cost of $69,000, Pratt Company recently purchased the following items for resale: Item No.of Items Purchased Resale Price Per unit M 4,000 $3.75 N 2,000 12.00 O 6,000 6.00 The appropriate cost per unit of inventory is: M N O $5.75 $5.75 $5.75 $3.38 $10.80 $5.40 $3.75 $12.00 $6.00 $3.45 $11.04 $5.52