The correct answer is:
Elkins Act.
The Elkins Act (1903) is a United States federal law that improved the Interstate Commerce Act of 1887. It allowed the Interstate Commerce Commission (ICC) to inflict onerous fines on railroads that offered rebates, and as well on the shippers that took these rebates. The railroad companies were not permitted to offer rebates. This act made railroad corporations, their officers, and their employees all liable for discriminatory practices.