If the Price of Wheat Is $25/bushel in the United

If the price of wheat is $25/bushel in the United States and $20/bushel in Canada,all of the following would tend to equalize prices EXCEPT:

A) when the U.S. imposes a tariff on Canadian wheat.
B) the Canadian dollar will appreciate.
C) when the domestic price of U.S. wheat falls.
D) the U.S. dollar will depreciate.
E) when the domestic price of Canadian wheat rises.