What did factory owners do to prevent unions from forming? they paid off union leaders so they would stay away. they had union leaders arrested for no cause. they only hired workers who promised they would not join a union. they used force to end union activities.

The answer is: They used force to end union activities

There are several things that the factory owners can do to force it. For example, they can ensure that all the union members would not have any chance of promotion. Or,

they can put the union members' name on 'blacklist' that would be shared to other companies. This will make it really hard for them to find new jobs if they decided to quit their current company.

its option c your welcome