NO.PZ2018111303000051
问题如下：
Felix is an CFA, work on the Equity investment company, one of the companies he follows, PZ Company, is based in China and complies with IFRS, Felix has found that PZ used 150 RMB million of its own cash and borrowed an equal amount to open a subsidiary in USA, the funds were converted into US dollars on 31 December 2018 at an exchange rate of 1 RMB= 6.9 US dollars, PZ also purchase 500$ million fixed asset and 200$ inventories. The price in US is increasing.
If RMB will appreciate against the USA dollar in the future, PZ ‘s gross profit margin would be highest if PZ using:
选项：
A.
LIFO and the current rate method
B.
FIFO and the current rate method
C.
FIFO and the temporal method
解释：
B is correct.
考点：temporal/current rate method
解析：
Gross profit margin=（revenue-COGS）/revenue，三种情况的revenue是相同的，我们只需要比较COGS，选一个转换后的COGS最低的。
子公司的LC=美元，母公司的RC=人民币，现在需要将美元转换成人民币，如果用乘法，汇率标价应该是人民币/美元。现在人民币升值，即美元贬值，汇率是下降的，因此美元转换成人民币，用人民币/美元的汇率，历史汇率＞平均汇率＞当前汇率。
temporal method下COGS用存货采购时的汇率转换，current rate method下COGS用平均汇率转换。因此：
A选项是较高的COGS价格和average的转换汇率。
B选项是较低的COGS价格和average的转换汇率。
C选项是是较低的COGS价格和较高的转换汇率。
首先B选项和C选项相比可以排除C。A选项和B选项相比可以排除A。
因此ABC三个选项相比，B选项转换后的COGS最低，B选项的gross profit margin最高。
老师请问我的推导哪里错了
