The railroad industry was primarily affected by the Interstate Commerce Act. The last option of the given question is the correct option. The Interstate Commerce Act was passed in the year 1887 as a Federal law of the United States of America. This Act came into existense to make sure that the rates charged by the railways was not unjustified. Also the government did not have the power to regulate or fix the rates. This act made sure that there was no discrimination in charges for long or short distance goods hauling. The railroads had to publicly declare their shipping rates to avoid any kind of discrimination.