Which Method Have Unions Been the Most Successful in Implementing

Multiple Choice

Which method have unions been the most successful in implementing in their dealings with MNCs?

A) ​Boycotts in multiple foreign markets.
B) ​Transnational bargaining.
C) ​Threat of widespread strikes in multiple nations.
D) ​Adoption of international codes of conduct to regulate MNCs' behavior.
E) ​Union organization on a local level only.