how did living in company towns make union membership more difficult for workers?

a. workers received free homes, food, and clothing.
b. company guards and agents spied on and reported workers.
c. workers made enough money that they did not need unions.
d. company stores did not sell goods to workers who joined a union.

i think d but i am not 100% sure. ! : )

I believe the answer is: d. Company stores did not sell goods to workers who joined a union.

And the working sites usually located far away from the metropolitan area (such as on top of the mountain or in the middle of the desert). This provide the workers with no other choice but to leave the union if they want to be a part of the work forces and live in company towns.

was found at b)south carolina

an era of negotiation.

is that an answer to your question?