Answer:
b. Congress refused to recognize Labor Day as a federal holiday.
Step-by-step explanation:
US President Grover Cleveland established Labor Day in September as an official holiday in the US, following the celebration of the Knights of Labor and to prevent May 1 from serving as a glorification of the "Chicago martyrs"
In U.S.A. they celebrated radical trade unionists, members of the workers' socialist party and the communist party on May 1st, identified as part of the international left "