At a lump-sum cost of $67500, Wildhorse Company recently purchased the following items for resale: Item No. of Items Purchased Resale Price Per Unit M 3700 $3.60 N 1850 11.70 O 5700 5.70 The appropriate cost per unit of inventory is: M N O $3.60 $11.71 $5.70 O $6.00 $6.00 $6.00 O $3.60 $11.70 $5.70 d $3.60 $11.71 $5.70