问题如下：
Under LIFO, XYZ company reported COGS of $500,000, and ending inventory of $600,000 in 2017, and in the footnotes record LIFO reserve increased $10,000, if XYZ company change accounting method, LIFO change to FIFO method, its cost of goods sold was:
选项：
A. $510,000
B. $500,000
C. $490,000
解释：
C is correct.
FIFO COGS = LIFO COGS –△LIFO reserve
=500,000-10,000=490,000.
这个题目为什么不用end的600,000来算？