Answer:
Option A: According to John Green, the union Knights of Labor disintegrated from over 700.000 members to zero because it was associated to violence and anarchism.
During the Haymarket Riot in 1886, incidents developed from a strike into a violent scenario, after someone threw a bomb to the police, resulting into eight casualties. Thereafter, public associated the image of this union with anarchism and savagery, losing all prestige and consequently its members.