Final answer:
The national minimum wage was not achieved during the Progressive Era; other reforms like tariff reform, railroad legislation, and banking reform were accomplished, but the minimum wage was established later in 1938. The correct option is d. a national minimum wage
Step-by-step explanation:
The reform that was not achieved during the Progressive Era, 1901-1914, is d. a national minimum wage. During this time, Progressives accomplished several legislative achievements including tariff reform through the Underwood Tariff Act, which lowered tariffs and implemented a federal income tax after the ratification of the 16th Amendment.
Railroad legislation was also a focus, with regulatory measures like the Hepburn Act of 1906, which allowed the Interstate Commerce Commission to set maximum railroad rates.
Banking reform was realized with the creation of the Federal Reserve System, which aimed to stabilize the banking industry and economy.
However, a national minimum wage was not established during the Progressive Era; this would only be introduced much later with the Fair Labor Standards Act of 1938. The correct option is d. a national minimum wage