Loire Co. has used the FIFO method since it began operations in Year 3. Loire changed to the weighted-average method for inventory measurement at the beginning of Year 6. This change was justified. In its Year 6 financial statements, Loire included comparative statements for Year 5 and Year 4. The following shows year-end inventory balances under the FIFO and weighted-average methods:

Year	FIFO	Weighted-Average
3	$ 90,000	$108,000
4	156,000	142,000
5	166,000	150,000

What adjustment, before taxes, should Loire make retrospectively to the balance reported for retained earnings at the beginning of Year 4?
A.	$18,000 increase.
B.	$18,000 decrease.
C.	$0
D.	$4,000 increase.