请问这里LIFO和FIFO价格是如何选的？

问题如下：

A laptop store reported the following laptop transactions for the year (in chronological order):

Assuming the laptop inventory was zero at the beginning, calculate the year-end laptop inventory using FIFO and LIFO under periodic system.

选项：

A.

B.

C.

解释：

B is correct.

Sold: 12 + 34 + 59 = 105

Available for sale: 50 + 30 + 80 = 160

Ending inventory: 160 - 105 = 55

Using FIFO: 55 x $60 = $3,300

Using LIFO: (5 x $50) + (50 x $40) = $2,250

考点：FIFO LIFO

LIFO是后进先出，当年总共卖掉了105件，让计算年底的inventory，60元的那批进了80件，当年都卖掉了，所以inventory里肯定不包含进价60的这批货，所以要从50算起。50元这批货当年卖掉了25件，还剩下5件，40元那批货一件都没卖掉，所以年末inventory金额是5件×50元+50件×40元=2250

FIFO先进先出，40块那批货全卖掉了，50块那批货也全卖掉了，60块那批货卖掉了25件，还剩55件，所以年末inventory剩下55件×60元=3300元。