When working with a perpetual inventory system, where should the 'Unit Price' in the Goods Receipt PO default from? 

The inventory account defined for each item in the Goods Receipt PO. 

The vendor's price list for each item in the Goods Receipt PO. 

The valuation method defined for each item in the Goods Receipt PO. 

The 'Item Cost' value of each item in the Goods Receipt PO.