A fishing fleet in Canada catches 4,000 kilos of salmon. The salmon is then sold to a processing facility in Canada, where it is cleaned and canned. One-third of the salmon goes on sale at Canadian supermarkets, and the rest is sold to a Canadian exporter. The exporter brings the Salmon into the United States, where it is sold to American distributors and sold in American supermarkets.

At which stage will currency need to be exchanged?
A) The fishing fleet sells salmon to a Canadian factory.
B) The factory sells salmon to Canadian supermarkets.
C) Consumers buy the Canadian salmon in American supermarkets.
D) The exporter sells to the American distributor.