D.They were viewed by potential employers as troublemakers.
Pullman strikers were viewed as trouble because they were able to shut down the entire railroad and put a stop to many industries.
As unions grew in power, employers were more and more concerned about strikes occurring. Strikes put a stop to work and unions promoted workers' rights which disrupted production. Those that participated in the Pullman strike were blacklisted by the power of Pullman himself and the publicity of the strike.