Which of the Following Statements Best Defines "Transnational Union Networks

Which of the following statements best defines "transnational union networks?"

A) Agreements between unions in different countries that allow members to easily transfer membership from one union to another.
B) Historical agreements between the Canadian Labour Congress and the American Federation of Labor.
C) Limitations on the rights of unions included in Free Trade Agreements between countries like Canada, the United States, and Mexico.
D) Linkages between unions in different parts of the world that allow them to pursue common goals like improved human rights.