The response that BEST describes the impact of the Interstate Commerce Act (1887) on business at the end of the 19th century is:
D While it had little immediate impact, it was the first federal law to put regulations on business in the United States.
The Interstate Commerce Act was significant as it marked the beginning of federal regulation of private industry, particularly in the railroad sector, laying the groundwork for future regulatory frameworks. Although its immediate effects were limited and it faced challenges in enforcement, it represented a shift towards government intervention in the economy.