The depreciation difference to be placed into the future temporary difference spreadsheet dated 12/31/x4 is:

		a. the difference between book and tax depreciation for 20x4
		b. the difference between book and tax depreciation for 20x5
		c. the difference between book and tax depreciation for all years before 20x5
		d. the difference between book and tax depreciation for all years after 20x4