A US Manufacturer Has Sold Goods to a Foreign Firm for for a Sale

A U.S. manufacturer has sold goods to a foreign firm for a sale price of 80,000 FC on 12/15/X1. The invoice is due 1/15/X2. The U.S. Firm fiscal year is 12/31/X1. Given the following exchange rates, what gain or loss would the U.S. firm record on 12/31?
12/15
1FC = $0.60 US Dollars
12/31
1FC = $0.65 US Dollars
1/15
1FC = $0.63 US Dollars

A) loss of $4,000
B) loss of $1,600
C) gain of $2,400
D) gain of $4,000