Which General Ledger Class(Item master Or Item Branch) has pickup in Purchase order during Purchase

The Item is defined as line type "N" , Stocking type "P" as procured Raw Materials and the Purcahse Price Level is "2". But the G/L class of the item ise different in item master from Item Branch/Item Branch location. Then what will be the G/L class pick up in Purchase order, the G/L Class of Item Master or G/L Class of Item Branch/Item Branch Location?