partnerships that are eligible to use the cash method of accounting for inventories may treat purchases of inventory items as materials and supplies that are not incidental and record the costs in which of the followingways? cost of inventory items are deducted in the year that the inventory item is purchased, costs of inventory items are expensesd based on the ratio of supplies on hand to supplies used, costs of inventory items are deducted in the year that the inventory item is sold or any of the aboce methods may be elected