问题如下：
A firm uses a perpetual inventory system. Which of the following statement is least appropriate?
选项：
A.If the firm now uses FIFO method and changes to use the periodic system, it will have an impact on the balance of inventory and COGS.
If the firm now uses LIFO method and changes the perpetual system to periodic system, then the balance of inventory will changes.
If the firm now uses LIFO method and changes to use weighted average cost method, then the COGS will changes.
解释：
A is correct.
Under the FIFO method and specific identification method, neither the perpetual system nor the periodic system will have an impact on the blance of inventory and COGS.
specific identification method指的是什么呢？
