Companies hired pinkertons to
a)move employees to company towns.
b)negotiate with unions in the workplace.
c)force scabs to cross picket lines.
d)report on and bust unions.

The correct is D) report on and bust unions.

Companies hired Pinkertons to report on and bust unions.

The Pinkertons were a detective agency in the United States, founded by Allan Pinkerton in 1850. One of the services of this agency was the infiltration in labor unions. Employers hired Pinkerton agents to infiltrate people in labor strikes during the 19th and 20th centuries. They supplied security and kept union strikers out of factories. They also were experts in hiring mercenaries to intimidate workers. So it is correct that Companies hired Pinkertons to report on and bust unions.