The correct option is B The Chauri Chaura incident
Non-cooperation movement was a movement organized by Mohandas Gandhi, to induce the British government of India to grant self-government, or swaraj, to India. The movement was suspended in February 1922 on account of Chauri Chaura incident. In Chauri Chaura, Uttar Pradesh, a violent mob set fire to a police station killing 22 policemen during a clash between the police and protesters of the movement. Gandhi discontinued the movement as the principle of ahimsa or nonviolence was violated.