What did factory owners do to prevent unions from forming?

a. they paid off union leaders so they would stay away.
b. they had union leaders arrested for no cause.
c. they only hired workers who promised they would not join a union.
d. they used force to end union activities.

The third alternative is correct (C).

The growth of the workers' movement through unionization generated a gross reaction of the bourgeoisie, which invested in the formation of private militias to fight the action of the unions, causing violence and death in the protests. However, the main strategy to sabotage collective groupings, was to establish as a criterion of hiring the non-affiliation of the worker to any union.

D. They used force to end union activities.

Governments and factory owners took steps to prevent unions from forming, these steps included:

viewed unions as an economic threat

believed unions were illegal

used force to end union activities