问题如下图：
选项：
A. 
B. 
C. 
解释：
请把“解释”解释一下，另外这个 unit是怎么定义的？
NO.PZ2017102901000039 不太懂 可否讲解一下
costs are creasing. levels are creasing. A is correct. LIFO reserve is the FIFO inventory value less the LIFO inventory value. In perio of rising inventory unit costs, the carrying amount of inventory unr FIFO will always exceethe carrying amount of inventory unr LIFO. The LIFO reserve mincrease over time a result of the increasing fferenbetween the olr costs useto value inventory unr LIFO anthe more recent costs useto value inventory unr FIFO. When inventory unit levels are creasing, the company will experiena LIFO liquition, recing the LIFO reserve. 老师，请问为什么 inventory unit level crease时一定会有lifo liquition？lifo liquition不是一种主动选择吗，主动选择不进新货卖便宜存货？
解析里的 LIFO reserve is the FIFO inventory value less the LIFO inventory value. In perio of rising inventory unit costs, the carrying amount of inventory unr FIFO will always exceethe carrying amount of inventory unr LIFO. The LIFO reserve mincrease over time a result of the increasing fferenbetween the olr costs useto value inventory unr LIFO anthe more recent costs useto value inventory unr FIFO. When inventory unit levels are creasing, the company will experiena LIFO liquition, recing the LIFO reserve. 加粗这句话没看懂。 啥叫 carrying amount？ 单价增的情况下，为啥 FIFO 的就永远大于 LIFO 的呢？不是应该 COGS 大于 inv，LIFO>FIFO 么？
这个助教的图里，reserve 是怎么体现的呢？横轴上两个红圈的距离么？还是怎样？如果价格上升，COGS 是往哪边移动呢？我不知道怎么单纯的通过这个图来判断
老师 LIFO reverse 和 LIFO liquition的区别和关系是什么？
