The correct answer is option 2: the Chauri-Chaura Incident.

The Non-Cooperation Movement was a significant movement led by Mahatma Gandhi in India during the 1920s as part of the Indian independence movement against British rule. The movement aimed to resist British rule through non-violent means and included various methods such as boycotting British institutions, shops, schools, and courts.

However, the movement was abruptly withdrawn following the Chauri-Chaura Incident. In Chauri-Chaura, a small town in Uttar Pradesh, a group of protesters clashed with the police on February 5, 1922. The protest turned violent, leading to the death of several police officers. In response, the protesters set fire to a police station, resulting in the deaths of 22 policemen.

Gandhi, who believed in the principles of non-violence, was shocked by the incident and believed that the movement had lost its non-violent character. He promptly withdrew the Non-Cooperation Movement, as he felt that the people were not yet ready for such a radical movement and needed more education on the principles of non-violence. Gandhi was deeply saddened by the incident and went on a fast to express his disapproval of the violence that had taken place.