Why Is It in the Best Interests of Workers in Canada

Why is it in the best interests of workers in Canada to work towards improving labour conditions in the developing world?

A) It is not in the best interests of Canadian workers to try to improve conditions elsewhere.
B) Workers in developing countries could afford more Canadian exports if they were paid more.
C) Canada's labour unions need more members.
D) Improving wages and working conditions in the developing world lowers the incentive for multinationals to move production out of core nations.