Which of the following best explains how the rise of machinery created an unfriendly relationship between industrialists and their employees? A. The industrialist earned his income from the work of others.
B. There was a lack of unions.
C. The employees were underpaid.

C

Explanation:

In as much as these are the only options given, then there has to be an answer there. Even though I fancy there being another answer.

But I'd say, the closest to the reason from the aforelisted is that the employees were underpaid. Since the advent of machineries, truth is that there wasn't going to be need for employees. This is because machines tend to have a much better output, better efficiency and won't need to be paid monthly in wages.

Since there isn't need for employees again, the industrialist tend to underpay the employees because they don't see their useful in the first instance

answer; is usually (less than) the socially optimal level of consumption;