Which of these is a weapon used by labor unions when negotiations with business owners fail

A. strike

B. lawsuit

C. court injunction

D. collective bargaining

The correct answer is A.

The main weapon used by labor unions when negotiations with business owners fail is the threat of a strike action.

When a strike happens, workers in a labor union stop working as a group. This results in the business needing to shut down. The longer the striker goes on for, the longer the business needs to remain shut.

Strikes are a reason why labor unions are more powerful than individuals. If one person goes on strike, it's easy for the business owner to fire that one person, however, it's more difficult to fire every single worker that goes on strike.