During the Last Few Years,the Benefits of Free Trade Agreements

During the last few years,the benefits of free trade agreements in North America have been slowly diminished by

A) the ups and downs of the Canadian dollar.
B) the reluctance of U.S.producers to sell goods to Canadian companies.
C) delays at border crossings between the United States and Canada.
D) higher inflation rates in the United States than in Canada.
E) objections from Mexico about unfair deals between the United States and Canada that shut Mexico out of export possibilities.