In which situation involving union activity would the government most likely get involved?

I don't know the options but just narrow this down yourself..

The freedom of workers to join together in unions and negotiate with employers (in a process known as collective bargaining) is widely recognized as a fundamental human right across the globe. In the United States, this right is protected by the U.S. Constitution and U.S. law and is supported by a majority of Americans.

whole lotta ptsd going on