I think the answer is either A or B
The correct answer is:
A violent or destructive protest
According to the law of rights, everyone is allowed to join a protest but in a peaceful manner. In case, the protest leads to extremism, then the government is authorized to take necessary actions, with the help of law enforcement officials, in order to control the situation. And hence the protestors can be arrested and accused of violating the rule of laws.
"<span>Supported by all of the Southern ex-Confederate governments" is the only incorrect statement, since the Radical Republicans were the harshest towards the South and therefore were hated by the ex-Confederates. </span>