Gross Profit Margin under Temporal and Current Rate Method

CFA Level II FRA
#1

One of the problems said to indicate if the gross profit margin will be higher, lower, or the same under the temporal rate method when compared to the current rate method, noting the following:

“Company A accounts for its inventory using the lower-of-cost-or-market valuation method in conjunction with the first-in, first-out, cost flow assumption. All of the inventory on hand at the beginning of the year was sold during 2016. Inventory remaining at the end of 2016 was acquired evenly throughout the year.”

I thought that under this particular situation the gross profit margin would have been the same regardless of whether we were using the temporal or current rate method because the problem stated the inventory was bought evenly throughout the year which means we would have used the average exchange rate.
Now I’m confused because I go the wrong answer

#2

Under the temporal method, non-monetary assets are converted at historical rates. So when you convert your inventory into COGS you need to use the rates that were in effect when the inventory was purchased and sold. This is similar to depreciation. It is converted at historical rates because it relates to a non-monetary asset.

#3

but what if your inventory throughout the year

#4

Beginning and ending inventory at historical rates. Purchases at the average rates if done throughout the year.

Ending Inventory= beginning inventory + purchases -COGS

So COGS is a mix of historical rates and average rate under the temporal method.