What Has Motivated Canadian Firms to Move Their Operations to Foreign

What has motivated Canadian firms to move their operations to foreign countries?

A) trade barriers, lower production costs, access to skilled workers, Canadian tax deferral
B) trade barriers, lower production costs, access to natural resources and manufacturing
C) import tariffs, foreign unions, foreign technology, expropriation
D) lower production costs, tax deferral, access to natural resources and manufacturing, expropriation