Answer:
The Correct answer is D) The boss refuses to address dangerous working conditions in the factories.
Step-by-step explanation:
Collective bargaining is when the workers union from a factory and the boss start to negotiate on something.
However, collective bargaining fails when negotiations fail. When no conclusion is reached, a Union might go on strike.
In the options given, option a,b,c does not result in the breaking down of negotiations, but option d is a classic example of how disagreements can cause problems in a company.