Answer wouldn’t be B because the Sherman Anti-Trust Act of 1890 forbade any restraint of commerce, which was used against labor unions. However, the Clayton Anti-Trust Act, passed during the progressive era, exempted unions from the Sherman Anti-Trust and stronger enforced the act. The Elkins and Mann-Elkins Acts didn’t really do anything for labor; they just gave the ICC more power to regulate railroads and interstate commerce, along with the Hepburn Act.
In short, best answer would be A.
The answer is a) the division of germany.