Answer:
A. Anarchists.
Explanation:
The Haymarket Riot is also referred to as the Haymarket Affair, Haymarket Massacre or Haymarket Incident, it occurred on the 4th of May, 1886 at Haymarket Square in Chicago, United States of America.
In 1886, a May Day was called by union leaders against the McCormick Harvesting Machine Company in Chicago and a picket line was created to prevent other workers from gaining entrance into the company.
On the 3rd of May, fight broke out between workers at the picket line and the police had to quickly intervene so as to restore law, peace and order.
Consequently, this intervention resulted in the death of some striking workers while others sustained injury. This prompted union leaders to organize an emergency meeting on the evening of the 4th of May, 1886 at the Haymarket Square in Chicago. In the course of this meeting, some radical labor activists (anarchists) started making inflammatory and inciting speeches that led to another chaos, which required the intervention of the police.
However, a bomb was thrown by someone at the police and it led to the fatal death of at least seven police officers while many others were injured. Eight radical labor activists (anarchists) were eventually arrested, tried and then convicted despite a lack of evidence, in connection with the murder caused by the bomb explosion.
In conclusion, members of the anarchist group were tried for murder following the Haymarket Riot.
